Through analyses, we found that PD-1 or PD-L1 inhibitors significantly increased the risk of developing rash for all grades (OR = 1.66, 95% CI: [1.31, 2.11]; I2 = 57%, Z = 4.19, p < 0.0001; Figures 2(a)–2(d)). This evidence concerns the gene PDCD1 and Skin rash.