CTLA4 and neoplasm: Recently, immune checkpoint inhibitors (ICIs) targeting programmed cell death protein (PD-1), programmed death-ligand (PD-L1), and T-lymphocyte-associated protein 4 (CTLA-4) have shown efficacies in restoring antitumor immunity in multiple tumor types with tolerable adverse-event profiles (Zheng et al., 2017; Ren and Zhang, 2019; Yost et al., 2019).