By contrast, LKB1-loss is associated with a low PD-L1 expression, as well as a lack of infiltrating CD8+ TILs, resulting in innate resistance to PD-1 inhibitors of patients with KRAS-mutant NSCLC (Skoulidis et al., 2015; Listì et al., 2018). The gene discussed is PDCD1; the disease is non-small cell lung carcinoma.