KRAS and lung cancer: Currently, targeted therapies have progressed rapidly, based upon the discovery of novel molecular markers such as mutations in EGFR (epidermal growth factor receptor), KRAS (V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog) genes and ALK (anaplastic lymphoma kinase) rearrangements[3-5], however, the overall progression-free survival rate of lung cancer patients is still suboptimal[6].