Owing to the aberrant glycosylation of PD-L1 in the ER, mediated by metformin, the combination of anti-CTLA4 antibody and metformin successfully invigorates a potent anti-cancer effect and enhances tumor elimination compared to the monotherapy in a syngeneic mouse model of melanoma, breast, and colon cancer (341). The gene discussed is CD274; the disease is neoplasm.