IL4 and neoplasm: In terms of tumor activity, elevated Th2 cytokines [interleukin‐4 (IL‐4), IL‐5, and IL‐13)] and decreased Th1 cytokines (IL‐2 and interferon γ (IFN‐γ)—interferon‐γ) suppress effective spontaneous antitumor immunity (Boyano et al., 1997; Boyano et al., 2000; Nevala et al., 2009).