The emerging development of tumor mutational burden in patients with NSCLC.

Immunocheckpoint inhibitors (ICIs) which target and CTLA-4 have dramatically changed the history of non-small-cell lung cancer treatment. Multiple biomarkers especially tumor mutational burden (TMB) have been raised to be potential predictors of response to ICIs. However, great value of TMB has been observed in patients who receive ICIs monotherapy instead of ICIs combination therapy from latest exploratory studies. Thus, the innovative concept of TMB needs to be identified. This study uncovers specific aspects of TMB including signatures of TMB, factors related with variation, racial differences, heterogeneity between tissue TMB and blood-based TMB. Additionally, more and more factors are found valuable in clinical trials, suggesting that more markers should be further investigated as interesting candidates for response prediction beyond TMB.