NAMI-A and KP1019 are two ruthenium anticancer agents that have entered clinical trials. NAMI is an acronym for "New Anti-tumour Metastasis Inhibitor", while the -A suffix indicates that this is the first of a potential series. NAMI-A and KP1019 are based primarily around the use of the metal ruthenium. Ruthenium is unknown to living systems, with a strong complex forming ability with numerous ligands. Its partially filled 4d sub-shell allows it to form complexes that are useful for a wide variety of applications including catalysis, electronics, photochemistry, biosensors and anticancer drugs. Ruthenium, unlike traditional platinum complexes such as cisplatin, shows greater resistance to hydrolysis and more selective action on tumors.