Compared to PD-1 monotherapy, hypophysitis more commonly occur during ipilimumab (an anti-CTLA4 mAb) monotherapy (OR, 0.29; 95% CI, 0.18–0.49; p < 0.001) than in combination therapy (OR, 2.2; 95% CI, 1.39–3.60; p = 0.001) [7]. Here, CTLA4 is linked to hypophysitis.