KRAS and lung cancer: While wild-type K-Ras serves as a suppressor of oncogenic activity, mutated K-Ras has been observed in cancers of the pancreas [36,37,38,39], esophagus [40], cardia and distal stomach [41], stomach [42,43], biliary tract, bile duct, ampulla, gallbladder [44], colon [45], and lung cancer [46,47,48].