As an alternative to PD-L1 as a companion biomarker, it should be recognized that tumor mutational burden (TMB), defined as the number of mutations per DNA megabase, is also promising biomarker for predicting immunotherapy responses in patients with advanced stage lung cancer.35 He et al36 developed and tested a non-invasive CT-based TMB predictor with 327 patients, which yielded high prognostic value in PFS and OS prediction of immunotherapy in patients with advanced NSCLC. Here, CD274 is linked to neoplasm.