GC and cancer: Based on their powerful abilities to stimulate proliferation of cytotoxic CD8+ T and NK cells, certain γc family cytokines such as IL-2 have long been used in clinical cancer immunotherapy.27 Since MARCH5 knockdown leads to higher level of γc in CD8+ T and NK cells, we reasoned that this would improve the efficacy of the γc family cytokines in anti-tumor immunotherapy.