Schalper et al., using a large cohort with 1,344 patients, show that high baseline plasma CXCL8 level is associated with poor clinical outcomes in participants with advanced melanoma, NSCLC, and renal-cell carcinoma (RCC) treated with nivolumab or ipilimumab, everolimus or docetaxel, which indicate that serum CXCL8 level is an unfavorable factor in tumor immunobiology and can act as an independently predictive biomarker in patients receiving ICIs (Schalper et al., 2020). Here, CXCL8 is linked to melanoma.