CD4 and neoplasm: B cells are increasingly considered as a crucial component in antitumor immunity, because of antigen presentation and cancer antibody production after differentiation into plasma cells.[130,131] Tumor-infiltrating B cells (TIL-B) have been found to be important for cancer immunotherapy, [132–134] contributing to the formation of CD4+ memory T cells and promoting the survival and proliferation of CD8+ T cells.