CTLA4 and melanoma: Immunotherapy with antibodies targeting cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) usually results in enterocolitis, and melanoma patients with anti-CTLA-4 enterocolitis took NSAIDs more frequently than patients without enterocolitis, which suggested that patients treated with anti-CTLA-4 were supposed to avoid NSAIDs (Marthey et al., 2016).