Different articles have pointed out that amplification or mutations of important protooncogenes including Kirsten rat sarcoma viral oncogene homolog (KRAS), TP53, and hepatocyte growth factor receptor (HGFR or c-MET) are significantly associated with high levels of mRNA and protein expression of PD-L1 in lung cancer [24–26]. The gene discussed is KRAS; the disease is lung cancer.