Abstract
The development of high-throughput sequencing of adaptive immune receptor repertoires (AIRR-seq of IG and TR rearrangements) has provided a new frontier for in-depth analysis of the immune system. The last decade has witnessed an explosion in protocols, experimental methodologies, and computational tools. In this chapter, we discuss the major considerations in planning a successful AIRR-seq experiment together with basic strategies for controlling and evaluating the outcome of the experiment. Members of the AIRR Community have authored several chapters in this edition, which cover step-by-step instructions to successfully conduct, analyze, and share an AIRR-seq project.
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References
- Boudinot P, Marriotti-Ferrandiz ME, Pasquier LD, Benmansour A, Cazenave PA, Six A (2008) New perspectives for large-scale repertoire analysis of immune receptors. Mol Immunol 45(9):2437–2445. https://doi.org/10.1016/j.molimm.2007.12.018 doi: 10.1016/j.molimm.2007.12.018. [DOI] [PubMed]
- Robins HS, Campregher PV, Srivastava SK, Wacher A, Turtle CJ, Kahsai O et al (2009) Comprehensive assessment of T-cell receptor beta-chain diversity in alphabeta T cells. Blood 114(19):4099–4107. https://doi.org/10.1182/blood-2009-04-217604 doi: 10.1182/blood-2009-04-217604. [DOI] [PMC free article] [PubMed]
- Georgiou G, Ippolito GC, Beausang J, Busse CE, Wardemann H, Quake SR (2014) The promise and challenge of high-throughput sequencing of the antibody repertoire. Nat Biotechnol 32(2):158–168. https://doi.org/10.1038/nbt.2782 doi: 10.1038/nbt.2782. [DOI] [PMC free article] [PubMed]
- Breden F, Luning Prak ET, Peters B, Rubelt F, Schramm CA, Busse CE et al (2017) Reproducibility and reuse of adaptive immune receptor repertoire data. Front Immunol 8:1418. https://doi.org/10.3389/fimmu.2017.01418 doi: 10.3389/fimmu.2017.01418. [DOI] [PMC free article] [PubMed]
- Tonegawa S (1983) Somatic generation of antibody diversity. Nature 302(5909):575–581. https://doi.org/10.1038/302575a0 doi: 10.1038/302575a0. [DOI] [PubMed]
- Sakano H, Kurosawa Y, Weigert M, Tonegawa S (1981) Identification and nucleotide sequence of a diversity DNA segment (D) of immunoglobulin heavy-chain genes. Nature 290(5807):562–565. https://doi.org/10.1038/290562a0 doi: 10.1038/290562a0. [DOI] [PubMed]
- Weigert MG, Cesari IM, Yonkovich SJ, Cohn M (1970) Variability in the lambda light chain sequences of mouse antibody. Nature 228(5276):1045–1047. https://doi.org/10.1038/2281045a0 doi: 10.1038/2281045a0. [DOI] [PubMed]
- Papavasiliou FN, Schatz DG (2002) Somatic hypermutation of immunoglobulin genes: merging mechanisms for genetic diversity. Cell 109(Suppl):S35–S44. https://doi.org/10.1016/s0092-8674(02)00706-7 doi: 10.1016/s0092-8674(02)00706-7. [DOI] [PubMed]
- Benichou J, Ben-Hamo R, Louzoun Y, Efroni S (2012) Rep-Seq: uncovering the immunological repertoire through next-generation sequencing. Immunology 135(3):183–191. https://doi.org/10.1111/j.1365-2567.2011.03527.x doi: 10.1111/j.1365-2567.2011.03527.x. [DOI] [PMC free article] [PubMed]
- Six A, Mariotti-Ferrandiz ME, Chaara W, Magadan S, Pham HP, Lefranc MP et al (2013) The past, present, and future of immune repertoire biology—the rise of next-generation repertoire analysis. Front Immunol 4:413. https://doi.org/10.3389/fimmu.2013.00413 doi: 10.3389/fimmu.2013.00413. [DOI] [PMC free article] [PubMed]
- Langerak AW, Bruggemann M, Davi F, Darzentas N, van Dongen JJM, Gonzalez D et al (2017) High-throughput immunogenetics for clinical and research applications in immunohematology: potential and challenges. J Immunol 198(10):3765–3774. https://doi.org/10.4049/jimmunol.1602050 doi: 10.4049/jimmunol.1602050. [DOI] [PubMed]
- Arnaout RA, Luning Prak ET, Schwab N, Rubelt F, the AIRR Community (2021) The future of blood testing is the immunome. Front Immunol. https://doi.org/10.3389/fimmu.2021.626793 doi: 10.3389/fimmu.2021.626793. [DOI] [PMC free article] [PubMed]
- Ghraichy M, Galson JD, Kelly DF, Truck J (2018) B-cell receptor repertoire sequencing in patients with primary immunodeficiency: a review. Immunology 153(2):145–160. https://doi.org/10.1111/imm.12865 doi: 10.1111/imm.12865. [DOI] [PMC free article] [PubMed]
- Gibson KL, Wu YC, Barnett Y, Duggan O, Vaughan R, Kondeatis E et al (2009) B-cell diversity decreases in old age and is correlated with poor health status. Aging Cell 8(1):18–25. https://doi.org/10.1111/j.1474-9726.2008.00443.x doi: 10.1111/j.1474-9726.2008.00443.x. [DOI] [PMC free article] [PubMed]
- Meng W, Zhang B, Schwartz GW, Rosenfeld AM, Ren D, Thome JJC et al (2017) An atlas of B-cell clonal distribution in the human body. Nat Biotechnol 35(9):879–884. https://doi.org/10.1038/nbt.3942 doi: 10.1038/nbt.3942. [DOI] [PMC free article] [PubMed]
- Kirsch IR, Watanabe R, O’Malley JT, Williamson DW, Scott LL, Elco CP et al (2015) TCR sequencing facilitates diagnosis and identifies mature T cells as the cell of origin in CTCL. Sci Transl Med 7(308):308ra158. https://doi.org/10.1126/scitranslmed.aaa9122 doi: 10.1126/scitranslmed.aaa9122. [DOI] [PMC free article] [PubMed]
- Dziubianau M, Hecht J, Kuchenbecker L, Sattler A, Stervbo U, Rodelsperger C et al (2013) TCR repertoire analysis by next generation sequencing allows complex differential diagnosis of T cell-related pathology. Am J Transplant 13(11):2842–2854. https://doi.org/10.1111/ajt.12431 doi: 10.1111/ajt.12431. [DOI] [PubMed]
- Hou D, Chen C, Seely EJ, Chen S, Song Y (2016) High-throughput sequencing-based immune repertoire study during infectious disease. Front Immunol 7:336. https://doi.org/10.3389/fimmu.2016.00336 doi: 10.3389/fimmu.2016.00336. [DOI] [PMC free article] [PubMed]
- Galson JD, Kelly DF, Truck J (2015) Identification of antigen-specific B-cell receptor sequences from the total B-cell repertoire. Crit Rev Immunol 35(6):463–478. https://doi.org/10.1615/CritRevImmunol.2016016462 doi: 10.1615/CritRevImmunol.2016016462. [DOI] [PubMed]
- Tipton CM, Fucile CF, Darce J, Chida A, Ichikawa T, Gregoretti I et al (2015) Diversity, cellular origin and autoreactivity of antibody-secreting cell population expansions in acute systemic lupus erythematosus. Nat Immunol 16(7):755–765. https://doi.org/10.1038/ni.3175 doi: 10.1038/ni.3175. [DOI] [PMC free article] [PubMed]
- Turner JS, Zhou JQ, Han J, Schmitz AJ, Rizk AA, Alsoussi WB et al (2020) Human germinal centres engage memory and naive B cells after influenza vaccination. Nature 586(7827):127–132. https://doi.org/10.1038/s41586-020-2711-0 doi: 10.1038/s41586-020-2711-0. [DOI] [PMC free article] [PubMed]
- Davis CW, Jackson KJL, McElroy AK, Halfmann P, Huang J, Chennareddy C et al (2019) Longitudinal analysis of the human B cell response to ebola virus infection. Cell 177(6):1566–1582.e1517. https://doi.org/10.1016/j.cell.2019.04.036 doi: 10.1016/j.cell.2019.04.036. [DOI] [PMC free article] [PubMed]
- Miho E, Yermanos A, Weber CR, Berger CT, Reddy ST, Greiff V (2018) Computational strategies for dissecting the high-dimensional complexity of adaptive immune repertoires. Front Immunol 9:224. https://doi.org/10.3389/fimmu.2018.00224 doi: 10.3389/fimmu.2018.00224. [DOI] [PMC free article] [PubMed]
- Robinson WH (2015) Sequencing the functional antibody repertoire—diagnostic and therapeutic discovery. Nat Rev Rheumatol 11(3):171–182. https://doi.org/10.1038/nrrheum.2014.220 doi: 10.1038/nrrheum.2014.220. [DOI] [PMC free article] [PubMed]
- Fink K (2019) Can we improve vaccine efficacy by targeting T and B cell repertoire convergence? Front Immunol 10:110. https://doi.org/10.3389/fimmu.2019.00110 doi: 10.3389/fimmu.2019.00110. [DOI] [PMC free article] [PubMed]
- Jiang N, Schonnesen AA, Ma KY (2019) Ushering in integrated T cell repertoire profiling in cancer. Trends Cancer 5(2):85–94. https://doi.org/10.1016/j.trecan.2018.11.005 doi: 10.1016/j.trecan.2018.11.005. [DOI] [PMC free article] [PubMed]
- Jacobsen LM, Posgai A, Seay HR, Haller MJ, Brusko TM (2017) T cell receptor profiling in type 1 diabetes. Curr Diab Rep 17(11):118. https://doi.org/10.1007/s11892-017-0946-4 doi: 10.1007/s11892-017-0946-4. [DOI] [PMC free article] [PubMed]
- Theil A, Wilhelm C, Kuhn M, Petzold A, Tuve S, Oelschlagel U et al (2017) T cell receptor repertoires after adoptive transfer of expanded allogeneic regulatory T cells. Clin Exp Immunol 187(2):316–324. https://doi.org/10.1111/cei.12887 doi: 10.1111/cei.12887. [DOI] [PMC free article] [PubMed]
- Sellner L, Bruggemann M, Schlitt M, Knecht H, Herrmann D, Reigl T et al (2017) GvL effects in T-prolymphocytic leukemia: evidence from MRD kinetics and TCR repertoire analyses. Bone Marrow Transplant 52(4):544–551. https://doi.org/10.1038/bmt.2016.305 doi: 10.1038/bmt.2016.305. [DOI] [PubMed]
- Stervbo U, Nienen M, Hecht J, Viebahn R, Amann K, Westhoff TH et al (2020) Differential diagnosis of interstitial allograft rejection and BKV nephropathy by T-cell receptor sequencing. Transplantation 104(4):e107–e108. https://doi.org/10.1097/TP.0000000000003054 doi: 10.1097/TP.0000000000003054. [DOI] [PubMed]
- Babel N, Stervbo U, Reinke P, Volk HD (2019) The identity card of T cells-clinical utility of T-cell receptor repertoire analysis in transplantation. Transplantation 103(8):1544–1555. https://doi.org/10.1097/TP.0000000000002776 doi: 10.1097/TP.0000000000002776. [DOI] [PubMed]
- Glanville J, Zhai W, Berka J, Telman D, Huerta G, Mehta GR et al (2009) Precise determination of the diversity of a combinatorial antibody library gives insight into the human immunoglobulin repertoire. Proc Natl Acad Sci U S A 106(48):20216–20221. https://doi.org/10.1073/pnas.0909775106 doi: 10.1073/pnas.0909775106. [DOI] [PMC free article] [PubMed]
- Rubelt F, Busse CE, Bukhari SAC, Burckert JP, Mariotti-Ferrandiz E, Cowell LG et al (2017) Adaptive Immune Receptor Repertoire Community recommendations for sharing immune-repertoire sequencing data. Nat Immunol 18(12):1274–1278. https://doi.org/10.1038/ni.3873 doi: 10.1038/ni.3873. [DOI] [PMC free article] [PubMed]
- DeWitt WS 3rd, Smith A, Schoch G, Hansen JA, Matsen FA, Bradley P (2018) Human T cell receptor occurrence patterns encode immune history, genetic background, and receptor specificity. eLife 7. https://doi.org/10.7554/eLife.38358 doi: 10.7554/eLife.38358. [DOI] [PMC free article] [PubMed]
- Szabo PA, Miron M, Farber DL (2019) Location, location, location: tissue resident memory T cells in mice and humans. Sci Immunol 4(34). https://doi.org/10.1126/sciimmunol.aas9673 doi: 10.1126/sciimmunol.aas9673. [DOI] [PMC free article] [PubMed]
- Kaestner KH, Powers AC, Naji A, Consortium H, Atkinson MA (2019) NIH initiative to improve understanding of the pancreas, islet, and autoimmunity in type 1 diabetes: the human pancreas analysis program (HPAP). Diabetes 68 (7):1394–1402. https://doi.org/10.2337/db19-0058 doi: 10.2337/db19-0058. [DOI] [PMC free article] [PubMed]
- Zhang J, Hu M, Wang B, Gao J, Wang L, Li L et al (2018) Comprehensive assessment of T-cell repertoire following autologous hematopoietic stem cell transplantation for treatment of type 1 diabetes using high-throughput sequencing. Pediatr Diabetes 19(7):1229–1237. https://doi.org/10.1111/pedi.12728 doi: 10.1111/pedi.12728. [DOI] [PubMed]
- Seay HR, Yusko E, Rothweiler SJ, Zhang L, Posgai AL, Campbell-Thompson M et al (2016) Tissue distribution and clonal diversity of the T and B cell repertoire in type 1 diabetes. JCI Insight 1(20):e88242. https://doi.org/10.1172/jci.insight.88242 doi: 10.1172/jci.insight.88242. [DOI] [PMC free article] [PubMed]
- Li H, Adamopoulos IE, Moulton VR, Stillman IE, Herbert Z, Moon JJ et al (2020) Systemic lupus erythematosus favors the generation of IL-17 producing double negative T cells. Nat Commun 11(1):2859. https://doi.org/10.1038/s41467-020-16636-4 doi: 10.1038/s41467-020-16636-4. [DOI] [PMC free article] [PubMed]
- Liu X, Zhang W, Zhao M, Fu L, Liu L, Wu J et al (2019) T cell receptor beta repertoires as novel diagnostic markers for systemic lupus erythematosus and rheumatoid arthritis. Ann Rheum Dis 78(8):1070–1078. https://doi.org/10.1136/annrheumdis-2019-215442 doi: 10.1136/annrheumdis-2019-215442. [DOI] [PubMed]
- Thapa DR, Tonikian R, Sun C, Liu M, Dearth A, Petri M et al (2015) Longitudinal analysis of peripheral blood T cell receptor diversity in patients with systemic lupus erythematosus by next-generation sequencing. Arthritis Res Ther 17:132. https://doi.org/10.1186/s13075-015-0655-9 doi: 10.1186/s13075-015-0655-9. [DOI] [PMC free article] [PubMed]
- Sui W, Hou X, Zou G, Che W, Yang M, Zheng C et al (2015) Composition and variation analysis of the TCR beta-chain CDR3 repertoire in systemic lupus erythematosus using high-throughput sequencing. Mol Immunol 67(2Pt B):455–464. https://doi.org/10.1016/j.molimm.2015.07.012 doi: 10.1016/j.molimm.2015.07.012. [DOI] [PubMed]
- Bashford-Rogers RJM, Bergamaschi L, McKinney EF, Pombal DC, Mescia F, Lee JC et al (2019) Analysis of the B cell receptor repertoire in six immune-mediated diseases. Nature 574(7776):122–126. https://doi.org/10.1038/s41586-019-1595-3 doi: 10.1038/s41586-019-1595-3. [DOI] [PMC free article] [PubMed]
- Bertram HC, Check IJ, Milano MA (2001) Immunophenotyping large B-cell lymphomas. Flow cytometric pitfalls and pathologic correlation. Am J Clin Pathol 116(2):191–203. https://doi.org/10.1309/BA3U-RMTU-D7UJ-M8DR doi: 10.1309/BA3U-RMTU-D7UJ-M8DR. [DOI] [PubMed]
- Barennes P, Quiniou V, Shugay M, Egorov ES, Davydov AN, Chudakov DM et al (2021) Benchmarking of T cell receptor repertoire profiling methods reveals large systematic biases. Nat Biotechnol 39(2):236–245. https://doi.org/10.1038/s41587-020-0656-3 doi: 10.1038/s41587-020-0656-3. [DOI] [PubMed]
- Kim SM, Bhonsle L, Besgen P, Nickel J, Backes A, Held K et al (2012) Analysis of the paired TCR alpha- and beta-chains of single human T cells. PLoS One 7(5):e37338. https://doi.org/10.1371/journal.pone.0037338 doi: 10.1371/journal.pone.0037338. [DOI] [PMC free article] [PubMed]
- Eugster A, Lindner A, Catani M, Heninger AK, Dahl A, Klemroth S et al (2015) High diversity in the TCR repertoire of GAD65 autoantigen-specific human CD4+ T cells. J Immunol 194(6):2531–2538. https://doi.org/10.4049/jimmunol.1403031 doi: 10.4049/jimmunol.1403031. [DOI] [PubMed]
- Ziegenhain C, Vieth B, Parekh S, Reinius B, Guillaumet-Adkins A, Smets M et al (2017) Comparative analysis of single-cell RNA sequencing methods. Mol Cell 65(4):631–643.e634. https://doi.org/10.1016/j.molcel.2017.01.023 doi: 10.1016/j.molcel.2017.01.023. [DOI] [PubMed]
- Afik S, Yates KB, Bi K, Darko S, Godec J, Gerdemann U et al (2017) Targeted reconstruction of T cell receptor sequence from single cell RNA-seq links CDR3 length to T cell differentiation state. Nucleic Acids Res 45(16):e148. https://doi.org/10.1093/nar/gkx615 doi: 10.1093/nar/gkx615. [DOI] [PMC free article] [PubMed]
- Stubbington MJT, Lonnberg T, Proserpio V, Clare S, Speak AO, Dougan G et al (2016) T cell fate and clonality inference from single-cell transcriptomes. Nat Methods 13(4):329–332. https://doi.org/10.1038/nmeth.3800 doi: 10.1038/nmeth.3800. [DOI] [PMC free article] [PubMed]
- Redmond D, Poran A, Elemento O (2016) Single-cell TCRseq: paired recovery of entire T-cell alpha and beta chain transcripts in T-cell receptors from single-cell RNAseq. Genome Med 8(1):80. https://doi.org/10.1186/s13073-016-0335-7 doi: 10.1186/s13073-016-0335-7. [DOI] [PMC free article] [PubMed]
- Eltahla AA, Rizzetto S, Pirozyan MR, Betz-Stablein BD, Venturi V, Kedzierska K et al (2016) Linking the T cell receptor to the single cell transcriptome in antigen-specific human T cells. Immunol Cell Biol 94(6):604–611. https://doi.org/10.1038/icb.2016.16 doi: 10.1038/icb.2016.16. [DOI] [PubMed]
- DeKosky BJ, Kojima T, Rodin A, Charab W, Ippolito GC, Ellington AD et al (2015) In-depth determination and analysis of the human paired heavy- and light-chain antibody repertoire. Nat Med 21(1):86–91. https://doi.org/10.1038/nm.3743 doi: 10.1038/nm.3743. [DOI] [PubMed]
- Klein AM, Macosko E (2017) InDrops and Drop-seq technologies for single-cell sequencing. Lab Chip 17(15):2540–2541. https://doi.org/10.1039/c7lc90070h doi: 10.1039/c7lc90070h. [DOI] [PubMed]
- Zemmour D, Zilionis R, Kiner E, Klein AM, Mathis D, Benoist C (2018) Single-cell gene expression reveals a landscape of regulatory T cell phenotypes shaped by the TCR. Nat Immunol 19(3):291–301. https://doi.org/10.1038/s41590-018-0051-0 doi: 10.1038/s41590-018-0051-0. [DOI] [PMC free article] [PubMed]
- Gerard A, Woolfe A, Mottet G, Reichen M, Castrillon C, Menrath V et al (2020) High-throughput single-cell activity-based screening and sequencing of antibodies using droplet microfluidics. Nat Biotechnol 38(6):715–721. https://doi.org/10.1038/s41587-020-0466-7 doi: 10.1038/s41587-020-0466-7. [DOI] [PubMed]
- van Dongen JJ, Langerak AW, Bruggemann M, Evans PA, Hummel M, Lavender FL et al (2003) Design and standardization of PCR primers and protocols for detection of clonal immunoglobulin and T-cell receptor gene recombinations in suspect lymphoproliferations: report of the BIOMED-2 Concerted Action BMH4-CT98-3936. Leukemia 17(12):2257–2317. https://doi.org/10.1038/sj.leu.2403202 doi: 10.1038/sj.leu.2403202. [DOI] [PubMed]
- Scheijen B, Meijers RWJ, Rijntjes J, van der Klift MY, Mobs M, Steinhilber J et al (2019) Next-generation sequencing of immunoglobulin gene rearrangements for clonality assessment: a technical feasibility study by EuroClonality-NGS. Leukemia 33(9):2227–2240. https://doi.org/10.1038/s41375-019-0508-7 doi: 10.1038/s41375-019-0508-7. [DOI] [PMC free article] [PubMed]
- Perry RP, Kelley DE, Coleclough C, Kearney JF (1981) Organization and expression of immunoglobulin genes in fetal liver hybridomas. Proc Natl Acad Sci U S A 78(1):247–251. https://doi.org/10.1073/pnas.78.1.247 doi: 10.1073/pnas.78.1.247. [DOI] [PMC free article] [PubMed]
- Carlson CS, Emerson RO, Sherwood AM, Desmarais C, Chung MW, Parsons JM et al (2013) Using synthetic templates to design an unbiased multiplex PCR assay. Nat Commun 4:2680. https://doi.org/10.1038/ncomms3680 doi: 10.1038/ncomms3680. [DOI] [PubMed]
- Friedensohn S, Lindner JM, Cornacchione V, Iazeolla M, Miho E, Zingg A et al (2018) Synthetic standards combined with error and bias correction improve the accuracy and quantitative resolution of antibody repertoire sequencing in human naive and memory B cells. Front Immunol 9:1401. https://doi.org/10.3389/fimmu.2018.01401 doi: 10.3389/fimmu.2018.01401. [DOI] [PMC free article] [PubMed]
- Brard F, Shannon M, Luning Prak ET, Litwin S, Weigert M (1999) Somatic mutation and light chain rearrangement generate autoimmunity in anti-single-stranded DNA transgenic MRL/lpr mice. J Exp Med 190(5):691–704. https://doi.org/10.1084/jem.190.5.691 doi: 10.1084/jem.190.5.691. [DOI] [PMC free article] [PubMed]
- Hieter PA, Korsmeyer SJ, Waldmann TA, Leder P (1981) Human immunoglobulin kappa light-chain genes are deleted or rearranged in lambda-producing B cells. Nature 290(5805):368–372. https://doi.org/10.1038/290368a0 doi: 10.1038/290368a0. [DOI] [PubMed]
- Rosenfeld AM, Meng W, Chen DY, Zhang B, Granot T, Farber DL et al (2018) Computational evaluation of B-cell clone sizes in bulk populations. Front Immunol 9:1472. https://doi.org/10.3389/fimmu.2018.01472 doi: 10.3389/fimmu.2018.01472. [DOI] [PMC free article] [PubMed]
- Japp AS, Meng W, Rosenfeld AM, Perry DJ, Thirawatananond P, Bacher RL et al (2021) TCR(+)/BCR(+) dual-expressing cells and their associated public BCR clonotype are not enriched in type 1 diabetes. Cell 184(3):827–839.e814. https://doi.org/10.1016/j.cell.2020.11.035 doi: 10.1016/j.cell.2020.11.035. [DOI] [PMC free article] [PubMed]
- Ye J, Ma N, Madden TL, Ostell JM (2013) IgBLAST: an immunoglobulin variable domain sequence analysis tool. Nucleic Acids Res 41(Web server issue):W34–W40. https://doi.org/10.1093/nar/gkt382 doi: 10.1093/nar/gkt382. [DOI] [PMC free article] [PubMed]
- MacConaill LE, Burns RT, Nag A, Coleman HA, Slevin MK, Giorda K et al (2018) Unique, dual-indexed sequencing adapters with UMIs effectively eliminate index cross-talk and significantly improve sensitivity of massively parallel sequencing. BMC Genomics 19(1):30. https://doi.org/10.1186/s12864-017-4428-5 doi: 10.1186/s12864-017-4428-5. [DOI] [PMC free article] [PubMed]
- Shuldiner AR, Nirula A, Roth J (1989) Hybrid DNA artifact from PCR of closely related target sequences. Nucleic Acids Res 17(11):4409. https://doi.org/10.1093/nar/17.11.4409 doi: 10.1093/nar/17.11.4409. [DOI] [PMC free article] [PubMed]
