KRAS and metastatic malignant neoplasm: The most frequently mutated genes across all metastatic cancers were TP53 (38%–58%) [121, 125, 130, 148] and EGFR (11%–49%) [125, 149], while EGFR (26%–28%), MET (4%–6%), KRAS (4%) and BRAF (3%) were most commonly identified in primary cancers [126, 131, 149].