CTLA4 and colitis: For instance, Renga et al. (2022), in a study on a murine model of melanoma, demonstrated that indole-3-carboxaldehyde (known to contribute to the maintenance of the intestinal barrier homeostasis) prevented intestinal damage associated with ICI-induced colitis and simultaneously did not interfere with the anti-cancer activity of anti-CTLA-4 therapy [43].