Similarly, Keegan and colleagues, in 47 metastatic NSCLC patients receiving anti-PD-(L)1 reported that patients with a > 40% increase or stable levels of IL-6 had reduced PFS compared to patients with decreases in IL-6 (median PFS: 4 vs. 11 months, p = 0.03) [39]. Here, IL6 is linked to non-small cell lung carcinoma.