CTLA4 and neoplasm: A recent study identified an upregulation of T cell immunoglobulin and mucin domain‐containing protein(TIM‐1) expression in B cells and limited the proliferative and tumor‐killing effects of T cells.[26] Blockade of TIM‐1 expression lowered the B‐cell receptor (BCR) activation threshold while enhancing the antigen presentation and co‐stimulatory functions of B cells.[26] A number of previous studies have also characterized the expression of tumor‐associated ICs on B cells, including CTLA‐4,[27] TIGIT,[28] PD‐L1,[29, 30] and others.