Netterberg I, et al. - In non-small cell lung cancer (NSCLC) patients, researchers evaluated circulating biomarkers as predictors of antitumor response to atezolizumab (anti-programmed death-ligand 1, Tecentriq). They assessed 95 plasma biomarkers in 88 patients with relapsed/refractory NSCLC receiving atezolizumab i.v. q3w (10–20 mg/kg) in the PCD4989g phase I clinical trial. They noted significant correlation of tumor shrinkage with area under the curve (AUC), baseline factors (metastatic sites, liver metastases, and smoking status), and relative change in interleukin (IL)-18 level from baseline at day 21 (RCFBIL-18,d21) when longitudinal kinetics of biomarkers and tumor size were modeled. However, a major predictor of tumor shrinkage was AUC, and they estimated the effect dissipated with an average half-life of 80 days, whereas RCFBIL-18,d21 seemed relevant to the duration of the response.