CTLA4 and colitis: In the monotherapy regimens, anti-PD1 treatment was mostly associated with skin (vitiligo-like depigmentation 12.2%, rash 9.5%) and endocrinological (thyroiditis 19%, hypophysitis 9.5%) toxicities, whereas colitis (34.7%) and skin rash (22.4%) were commonly observed in single-agent anti-CTLA4 (Figure 3A).