CTLA4 and acute kidney injury: When different ICIs were combined with PPIs, we found that PD-1 monotherapy combined with PPIs was associated with the highest risk of rAEs (OR 1.72, 95%CI 1.01–2.95, p = 0.046), contrasting with the common belief that combinations of anti-CTLA-4 and anti-PD-1 or anti-PD-L1 pose the greatest AKI risk [5,8,17].