All of our cells contain a gene called KRAS that regulates the signaling pathways responsible for cell proliferation, differentiation, and survival. If a mutation occurs in a KRAS gene, it may allow cancer cells to multiply out of control. KRAS mutations (KRAS+) are a common driver of cancer because KRAS is the most frequently mutated oncogene.
Testing for KRAS+ and the specific gene mutation is done by a pathologist on the actual tumor tissue.