CD5 and B-cell non-Hodgkin lymphoma: CD5 is also expressed on regulatory B cells that involve in immune evasion.42, 43 CD43 has been shown to be expressed on early hematopoietic cells derived from human embryonic stem cells (hESCs), pro‐B, and early‐stage pre‐B cells including B‐1 and B‐2 cells, which have lost CD43 expression in late stage.44, 45 Some earlier studies in mice indicated that B‐1a cells may be the origin of some B‐cell lymphomas.46, 47 Coexpression of CD5/CD43 can only be found in B‐1a cells in mice, which appear early in B‐cell development and have many functions of primitive cells.