CD274 and non-small cell lung carcinoma: Current studies pointed that PD-L1, tumor mutational burden (TMB), and intratumoral heterogeneity may provide hints of prognosis with immunotherapy in NSCLC—for instance, a high TMB (>10 mutations/megabase) can select patients with NSCLC who may benefit from ICB, irrespective of the expression levels of PD-L1.