PDCD1 and non-small cell lung carcinoma: The synergy of MEKi with anti-PD-1/PD-L1 antibodies has been previously reported in NSCLC [12, 56], but none of these studies provide mechanistic evidence for trametinib-mediated sensitization of KRAS-mutant LUAD human tumors to PD-1/PD-L1 blockade.