CTLA4 and colitis: The study did not observe any noticeable difference between the control group and PD-1 therapy concerning these adverse events.43 According to Abdel-Rahman et al., patients taking PD-1 and CTLA-4 inhibitors are more likely to develop colitis and diarrhea of all grades, as well as high grades of diarrhea.44 In the study findings, patients treated with a combination of PD-1 and CTLA-4 exhibited a higher incidence of any grade of TRAEs compared to the control group (35% vs. 40%, P = 0.04).