Several immunotherapy drugs including those that block programmed cell death 1 ligand (PD-1), programmed cell death ligand 1(PD-L1), and cytotoxic T lymphocyte-associated protein 4 (CTLA-4) are now indicated as first- or second-line therapy for many solid tumors including melanoma, non-small cell lung cancer, bladder cancer, and renal cell cancer among others [8]. The gene discussed is CTLA4; the disease is urinary bladder cancer.