KRAS and lung adenocarcinoma: These gene fusions are mutually exclusive with each other and with mutations of other oncogenes, such as EGFR (epidermal growth factor receptor), KRAS (Kirsten rat sarcoma viral oncogene homolog), BRAF (B-Raf proto-oncogene), and ERBB2 (erb-b2 receptor tyrosine kinase 2), in lung adenocarcinoma (LADC) (Figure 1) [1,2,3].