Oyanagi J, et al. - In patients with non-small-cell lung cancer (NSCLC) treated with nivolumab monotherapy, researchers assessed serum proteins pertinent to immune checkpoint blockade to find non-invasive predictive biomarkers. Nivolumab monotherapy (3 mg/kg, Q2W) was given to patients with advanced NSCLC who had failed at least one previous chemotherapy regimen until progressive disease or unacceptable toxicity was seen. Findings suggested an association of follistatin and IP-10 levels with durable clinical benefit, and that serum RANTES levels are linked with immune-related adverse event (irAE) onset. According to findings, serum proteins in patients with NSCLC treated with nivolumab have the potential to be predictive markers for a durable clinical benefit and irAEs onset; the same mechanisms may not regulate antitumor activity and irAEs.