CD274 and neoplasm: However, despite higher PD-L1 expression, ALK+ tumors also harbored several features of inert immune tumor microenvironments, including decreased CD8+ T cells (fold change −1.3; P < 0.001) and lower TMB (median 3 mutations/mb) when compared with KRAS+ and EGFR+ tumors (nine for KRAS-mutated vs. four for EGFR-mutated tumors; P < 0.001; ref. 59).