KRAS is the most frequentlymutated human oncogene,accounting for 30% of all human cancers. It has taken three decades for researchers to find the first moleculesto bind K-Ras, against one particular mutant G12C that has a chemicallytractable acquired Cys12. These covalentallosteric inhibitors cross-link Cys12 and bind to a cryptic pocketnow known as the Switch-II Pocket (S-IIP). This evidence concerns the gene KRAS and cancer.