CTLA4 and neoplasm: T‐cell‐expressed ICs associated with tumors, including PD‐1, CTLA‐4, and TIGIT, are also aberrantly upregulated in B cells and are associated with pro‐tumor immunity.[27, 28, 50, 92, 93, 94] In addition, the same class of IC signals expressed by both B cells and T cells can influence the antitumor effects of T cells.