HUN47990 is a bisphosphonate (BP) prodrug with antitumor activity. HUN47990 potently inhibits the in vitro growth of a variety of tumor cell lines, especially hematopoietic cell lines, at nanomolar concentrations. HUN47990 inhibited the prenylation of the RAP1A small GTPase signaling protein at concentrations as low as 1-10 nM. HUN47990 slowed the growth of human bladder cancer cells in an immunodeficient mouse model. HUN47990 is significantly more active than zoledronic acid, the most active FDA-approved BP, and a potential anti-cancer therapeutic. HUN47990 was first reported in ChemMedChem. 2016 Dec 16;11(24):2656-2663 (compound 7). This product has no formal name at the moment. For the convenience of communication, a temporary code name was therefore proposed according to MedKoo Chemical Nomenclature (see web page: https://www.medkoo.com/page/naming).