KRAS and cancer: The presence of mutated K-ras (Kirsten ras GTPase) in cancer cells is associated with a poor prognosis of the cancer patients due in part to the activation of several signaling pathways (e.g., nuclear factor kappa-B(NF-κB) and mitogen-activated protein kinase (MAPK)) by K-ras to enhance cell proliferation, migration, and invasion [5,6].