IL2 and neoplasm: Each subset can secrete different cytokines; Th1 cells primarily secrete interferon-γ (IFN-γ), IL-2, and tumor necrosis factor-alpha (TNF-α); activated Th1 cells and the cytokines that they secrete have a strong antitumor activity and immunomodulatory effect and can play a positive regulatory role in the tumor immune microenvironment.