Specifically, type 1 (M1) macrophages and Th1 cells reinforce one another, with M1‐produced IL‐12 maintaining the Th1 phenotype and Th1‐produced IFN‐γ maintaining the M1 phenotype.91 In this Th1‐driven environment, pro‐inflammatory cytokines such as tumor necrosis factor (TNF)‐α, IL‐1, and IL‐6 are also involved in cancer elimination by stimulating various aspects of antitumor immunity, including recruitment of macrophages and T cells from the circulation and stimulation of leukocyte tumoricidal functions.91 This evidence concerns the gene IL1B and cancer.