In particular, K-Ras harboring a cysteine mutation at position 12 is commonly found in K-Ras associated cancers, including lung, pancreatic, and colorectal adenocarcinomas (Stephen et al. 2014; Prior et al. 2012), and has become a target for therapeutic intervention using cysteine-reactive covalent small molecule inhibitors (Janes et al. 2018; Prior et al. 2012; Ostrem et al. 2013). This evidence concerns the gene KRAS and cancer.