IL2 and cancer: Th1 cells promote cell-mediated immunity [16] via production of interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), interleukin-2 (IL-2), and interleukin-12 (IL-12) [17], which play a substantial role in recognizing cancer cells and inhibiting their progression by activation of CTL, macrophages [18], and NK cell activity, and upregulation of major histocompatibility complex (MHC) expression on antigen-presenting cells (APCs) [17].