IL2 and cancer: Cytokine-induced killer (CIK) cells, a widely studied cell-based immunotherapy for cancer treatment, are generated ex vivo by culturing peripheral blood mononuclear cells (PBMC) with the timely addition of interferon gamma (IFN- γ), monoclonal antibody against CD3 (anti-CD3) and interleukin-2 (IL-2) for 3–4 weeks.