PDCD1 and lung adenocarcinoma: Thus, recent clinical studies have shown that LKB1 genetic alterations are associated with lack fo benefit from PD-1 blockade (7% overall response) in KRAS-mutant lung adenocarcinomas, a phenomenon that cannot be related to KRAS mutations in that KRAS-mutant lung adenocarcinomas without LKB1 mutations are responsive (about 35% of overall responses) to PD-1 blocking [354].