CD274 and pneumonitis: Zhou et al.’s [32] meta-analysis showed that incidences of serious adverse event (rash, hepatobiliary disorders, pneumonitis, and colitis) were 37% in the chemotherapy arm, 37% in PD-L1, and 33% in the PD-1 arm, while 47% in combined groups of PD-L1 plus chemotherapy and 43% in the PD-L1 plus chemotherapy arm [32].