Diagram illustrating the possible phylogenetic relationship between human SULT genes and pseudogenes. Phylogenic tree was prepared with CDS nucleotide sequences of SULT1A1 (NM_001055), SULT1A2 (NM_001054), SULT1A3 (NM_177552), SULT1A4(NM_001017390), SULT1B1 (NM_014465), SULT1C2 (NM_001056), SULT1C3a (NM_001320878), SULT1C4 (NM_006588), SULT1C5P(AK056906), SULT1D1P (NG_002642), SULT1D2P (NC_000003.12), SULT1E1 (NM_005420), SULT2A1 (NM_003167), SULT2A2P (), SULT2B1b (NM_177973), SULT3A1P (NC_000014), SULT4A1 (NM_014351), SULT6A1 (NM_001367551). Hypothetical CDS nucleotide sequences of SULT1D1P were generated from the regions of exons 2 - 8 based on the NG_002642. For SULT1D2P, NC_000003.12, containing exons 2 - 8, was directly used as hypothetical CDS nucleotide sequences of SULT1D2P. For SULT1C5P, exons 2 - 7 were retrieved from AK056906 and NC_000002.12 using BLAST search as hypothetical CDS nucleotide sequences of SULT1C5P. For SULT2A2P, exons 2 - 3 were retrieved from NC_000019.10 using BLAST search as hypothetical CDS nucleotide sequences of SULT2A2P. For SULT3A1P, NC_000014, containing exons 2 - 7, was directly used as hypothetical CDS nucleotide sequences of SULT3A1P. Analysis of aligned sequence data was carried out in MEGA 11 ALPHA.