PDCD1 and pneumonitis: As shown in Figures 1, 2, compared with chemotherapy, PD-1 inhibitors showed significant increase in grade 1-5 and grade 3-5 pneumonitis (RR,5.17, 95% CI: 2.82-9.47, p < 0.001, RR,4.14, 95% CI:1.82-9.42, p < 0.001),but not in pneumonia.