The pooled results demonstrated that the pretreatment peripheral levels of IL-6 (univariate analysis: HR = 2.53, 95% CI = 2.21-2.89, <i>p</i> < 0.00001; multivariate analysis: HR = 2.21, 95% CI = 1.67-2.93, <i>p</i> < 0.00001) and IL-8 (univariate analysis: HR = 2.17, 95% CI = 1.98-2.38, <i>p</i> < 0.00001; multivariate analysis: HR = 1.88, 95% CI= 1.70-2.07, <i>p</i> < 0.00001) were significantly associated with worse OS of cancer patients receiving ICI treatment in both univariate and multivariate analysis. The gene discussed is CXCL8; the disease is cancer.