Avelumab (Bavencio®) is a PD-L1 inhibitor from the IgG1 subclass, approved by the FDA in 2017 for urothelial carcinoma, Merkel cell carcinoma and renal cell carcinoma (13, 83), while inducing hypothyroidism as irAE (64). The gene discussed is CD274; the disease is urothelial carcinoma.