KRAS, member of the RAS family of small GTPases which functions as an upstream regulator of the MAPK and PI3K pathways, is frequently mutated in a diverse range of cancers including pancreatic, colorectal and lung cancers. More than 90% of pancreatic ductal adenocarcinoma samples have a KRAS mutation which may have prognostic, and (with ongoing trials assessing the efficacy of novel KRAS inhibitors) possibly therapeutic implications. However, targeting KRAS directly has been difficult in these tumors. KRAS mutations are infrequent in gastric carcinomas and have been reported in approximately 6% of cases. The gain of function KRAS G12D mutation is known to be oncogenic.