KRAS and colorectal carcinoma: The presence of KRAS mutation occurs in 35% to 45% of metastatic CRC (Andreyev et al., 2001; Andreyev, Norman, Cunningham, Oates, & Clarke, 1998; Lievre et al., 2006; Neumann, Zeindl-Eberhart, Kirchner, & Jung, 2009; Richman et al., 2009) and has been shown to be associated with a worse prognosis in both metastatic and high-risk stage II/stage III CRC (Andreyev et al., 2001; Andreyev et al., 1998).