Mutations in the ras oncogene are present in many human cancers, including 30-50% of colon and 90% of pancreatic cancer. 1, 2 The Ras protein undergoes a series of post- translational modifications, including S-farnesylation of a cysteine residue located in the C- terminal tetrapeptide, a region of the molecule referred to as the “CaaX box”(C) cysteine, a) any aliphatic amino acid, X) a prenylation specificity residue). 2 The enzyme ...
