Table 1.

Association of circRNAs with the development and functions of immune cells

CircRNAs	Immune cells	Expression state	Functions	References
circ-FNDC3B, circ-ELK4, circ-MYBL1 and circ-SLFN12L	Differentiated lymphoid and myeloid cells	Differentially expressed in differentiated lymphoid and myeloid cells	Probably regulated the differentiation and cellular function in hematopoietic cells	39
189 differentially expressed circRNAs such as circRNA-010231	Macrophages	Differentially expressed in the M1 compared with the M2 macrophages	Involved in the differentiation and polarization of macrophages	41
1356 new identified circRNAs	Human humoral immune B cells	Differentially expressed in different plasma cells	Exquisitely controlled rearrangement of the Ig during the humoral immune response	42
mmu_circRNA_007893	Macrophages	Upregulated in CGRP-stimulated macrophages	Mediated the IL-6 expression by working as an mmu-miR-485-5p sponge	43
circRNA_100783	CD8+ T cells	Upregulated in C1 (CD28(+)CD8+ vs CD28(−)CD8+ T cells in the elderly) and C4 (CD28(−)CD8+ T cells in the elderly vs in the adult) cross-comparisons	Possibly regulated phosphoprotein-related signal transduction on CD28-dependent CD8+ T-cell ageing	45
circANRIL	Macrophages	-	Disrupted pre-rRNA processing and ribosome biogenesis by binding to PES1, which induced apoptosis and inhibited proliferation	46
circRNAs from TLR6 and MYO1F	Neutrophils	-	Possibly affected the expression of parental immune genes	47

Ig Immunoglobulin, CGRP Calcitonin gene-related peptide, IL-6 Interleukin-6, PES1 Pescadillo homolog 1, TLR6 Toll-like receptor 6, MYO1F Myosin 1F