Early in 1891, Willam Cooley attempted to treat sarcoma via intratumoral injections of Streptococcus pyogenes and Serratia marcescens to activate immunity.1 Currently, the most commonly used strategy is the inhibition of immune checkpoints, particularly targeting the programmed cell death receptor-1 (PD-1), and its ligand, programmed cell death ligand-1 (PD-L1) and cytotoxic T lymphocyte-associated protein 4 (CTLA4).2 Nivolumab, pembrolizumab and camrelizumab are approved PD-1 blocking agents, while atezolizumab, avelumab, and durvalumab are approved PD-L1 blocking antibodies. The gene discussed is CTLA4; the disease is sarcoma.