IL15 and neoplasm: According to recently published single-cell analysis data, both CD4(+) TH cells and CD8(+) cytotoxic T cells are equally effective in direct tumor cell killing, and their cytotoxicity is associated with both TH1 and TH2 cytokines, e.g., IFN-γ, TNF-α, IL-15, and IL-13, as confirmed by the expression of master transcription factor genes TBX21 and GATA3 [49, 50].