In patients with non-small cell lung cancer (NSCLC), the most frequent oncogene driver mutation in Western countries is Kirsten rat sarcoma viral oncogene homolog (KRAS), and KRAS-mutant NSCLC is associated with smoking. There are various sources of biological heterogeneity of KRAS-mutant NSCLC, including different genotypes that may be associated with specific clinical outcomes, the presence of other co-mutations that exhibit different biological features and drug sensitivity patterns, and mutant allelic content. The efficacy of chemotherapy in patients with KRAS-mutant NSCLC is generally poor and numerous novel therapeutic strategies have been developed. These approaches include targeting KRAS membrane associations, targeting downstream signalling pathways, the use of KRAS synthetic lethality, direct targeting of KRAS, and immunotherapy. Of these, immunotherapy may be one of the most promising treatment approaches for patients with KRAS-mutant NSCLC. Recent data also suggest the potential for distinct efficacy of immunotherapy according to the presence of other co-mutations. In view of the biological heterogeneity of KRAS-mutant NSCLC, treatment will likely need to be individualised and, in future, may require the use of rational combinations of treatment, many of which are currently under investigation. 1. Introduction Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations are found in approximately 20-25% of lung adenocarcinomas in Western countries [1-3] and in approximately 10-15% of cases in Asia [4,5]. Considered globally, KRAS-mutant tumours constitute the most frequent potentially targetable molecular subtype of non-small-cell lung cancer (NSCLC) [6]. As is the case with the vast majority of potentially

We found a high discrepancy of driver mutations among NSCLC patients with GGNs and a favorable prognosis after multiple lesions resection, which support surgical resection in this situation as a reasonable approach.