These results suggest that KRAS-LCS6 genotype is an insufficient predictor of outcome by itself and they provide insight into the conflicting body of literature surrounding clinical utility of KRAS-LCS6 genetic testing in the clinical management of this disease, demonstrating the complexity of colorectal cancer and the need for additional, more complex batteries of molecular markers to optimize therapeutic regimens guided by precision medicine approaches. This evidence concerns the gene KRAS and colorectal cancer.