CTLA4 and neoplasm: Some of the most widely studied immunotherapies include immune checkpoint inhibitors (ICIs) such as anti–PD-1 (aPD-1) and anti–CTLA-4 antibodies, which relieve inhibitory signaling pathways that restrain T cell activation and adoptive cell therapies (ACT), which supply patients with ex vivo–expanded, tumor-reactive lymphocytes to enhance cytotoxic responses [2,3].