CTLA4 and melanoma: Stat3+/+ melanoma-bearing mice with acquired gastrointestinal impairment by Citrobacter rodentium infection and dextran sodium sulfate treatment displayed a predilection for anti-CTLA-4-mediated irAEs, with accumulation of neutrophils, cytotoxic and IFN-γ+ CD8+ and CD4+ T cells, and inflammatory cytokines such as IFN-γ and IL-6 in the colon (54).