KRAS and neoplasm: A similar genetic heterogeneity in SR conferring driver mutations was found in model BoC106, with one SR tumor (BoC106 C8) carrying a BRAF mutation (N518I, described as low-activity or kinase-dead BRAF mutant [57], and therefore not considered as a driver mutation herein), a second (BoC106 C2) developing an amplification (chr12:22615401-26669741) including the KRAS gene locus (Fig. 4a, b), while the third tumor (BoC106 C6) did not reveal an obvious driver gene alteration.