EGFR and neoplasm: Notably, immunohistochemistry and western blotting analysis of tumor biopsies obtained from alveolar adenocarcinoma patients showed that PD-L1 phosphorylation levels at Ser279 are higher in EGFR-WT tumors compared to EGFR-mutant-driven tumors, and this difference in phosphorylation levels correlated with lower PD-L1 levels in EGFR-WT tumors (Fig. 2h–k).