Five studies (466 patients) analyzed the impact of IL-8 expression in CRC patients who had all received treatment with anti-angiogenic agents (with or without chemotherapy); high IL-8 expression significantly correlated with worse OS (pooled HR by random effect model: 3.427; 95% CI: 2.446–4.802; p < 0.001; Figure 6A) and PFS (pooled HR by random effect model: 3.237; 95% CI: 1.684–6.219; p < 0.001; Figure 6B), with low heterogeneity between studies for OS and high heterogeneity for PFS (I2: 1.718 and 55.180, respectively). This evidence concerns the gene CXCL8 and colorectal carcinoma.