In another study of stage IV NSCLC patients (n = 29), Kauffmann-Guerrero et al. found that individuals with higher baseline serum IL-8 (≥ 19.67 pg/ml) had a lower response rate (p = 0.006) and reduced PFS (p = 0.030, median PFS 4.0 weeks vs. 19.71 weeks) following anti-PD-1 than patients with IL-8 below this threshold [26]. The gene discussed is CXCL8; the disease is non-small cell lung carcinoma.