MSCs can be engineered with genes encoding enzymes that can convert non-active pro-drugs into active molecules, such as MSCs engineered with the cytosine deaminase-uracil phosphoribosyl transferase (CD-UPRT) gene, encoding for the CD-UPRT enzyme that allows the transformation of the pro-drug 5-fluorocytosine (5-FC) into the anti-cancer drug 5-fluorouracil (5-FU). This evidence concerns the gene UPRT and cancer.