KRAS and colorectal cancer: The aim of this research was to perform a preclinical evaluation of the (2S)-N-(2,5-diiodophenyl)-2-[(3,4-dimethoxiphenyl)methylamine] propenamide (I-C19 and 131I-C19) and establish its uptake, affinity, biokinetics, cytotoxic and radiotoxic effects in colorectal cancer cells and tumors with mutated K-Ras4B.