Using different antibodies, including E1L3N, 22C3, 28–8, SP142, and SP263, PD-L1 subgroups were defined as negative (PD − L1 < 1%), intermediate (PD-L1 1-49%), and high (PD − L1 ≥ 50%), and mutations in KRAS, TP53, and MET were demonstrated to be associated with PD-L1 high expression and STK11 mutations associated with PD-L1 negativity in American patients with lung adenocarcinomas [44]. This evidence concerns the gene KRAS and lung adenocarcinoma.