Traditional systematic reviews and meta‐analyses were conducted to estimate the safety profile of PD1/PD‐L1 inhibitor.13, 14, 15, 16 However, due to lacking head‐to‐head direct evidence, comparative pneumonitis risk among different PD1/PD‐L1 inhibitor‐related therapeutic regimens have never been systematically studied. The gene discussed is PDCD1; the disease is pneumonitis.