CD4+ T helper cells exhibit a profound effect in initiating and maintaining anti-tumor immunity: secretion of Th1 cytokines such as IL-2 and IFN-γ promote CD8+ cytotoxic and natural killer cell function (Kim and Cantor, 2014), as well as induction of MHC class II molecule expression on tumor cells (Mortenson and Fu, 2014). Here, CD4 is linked to neoplasm.