FAP is a serine protease overexpressed onthe cancer-associated fibroblasts of over 90% of epithelial tumors,such as breast, colorectal, head and neck, lung, ovarian, and pancreaticadenocarcinomas. Recently, FAP inhibitors(FAPi) have been successfully integrated in the design of radiopharmaceuticalsfor targeted theranostic applications, and a similar approach could be envisaged for the obtainment ofoncotargeted Ru­(II) MTs. The gene discussed is FAP; the disease is cancer.