Tissue‐based TMB (tTMB) is an emerging biomarker of response to checkpoint inhibitor treatment.26, 27 Recent studies have reported the utility of bTMB in predicting the clinical outcomes.6 In EGFR‐TKI treatment, TMB is rarely discussed since tumours with EGFR sensitive mutation usually have a low TMB. This evidence concerns the gene EGFR and neoplasm.