KRAS and non-small cell lung carcinoma: The key “driver oncogenes” that have been associated with NSCLC include Kirsten rat sarcoma viral oncogene homolog (KRAS) and several receptor tyrosine kinases (RTK) such as the epidermal growth factor receptor (EGFR), platelet-derived growth factor receptor (PDGFR), anaplastic lymphoma kinase (ALK) and hepatocyte growth factor receptor (HGFR/MET) [3].