B cells act as antigen-presenting cells to present tumor-associated antigen (TAA) to CD4+ T cells [18], and then help CD4+ and CD8+ T cells to secrete interferon-γ, resulting in immediate cytotoxicity to tumor cells [18,19]; meanwhile, B cells directly lyse tumor cells by secreting granzyme B and TRAIL [20]. This evidence concerns the gene CD4 and neoplasm.