2-(1-Oxo-2(1H)-naphthalenylidene)-hydrazinecarboxamide-d4 is labelled 2-(1-Oxo-2(1H)-naphthalenylidene)-hydrazinecarboxamide (N359270) which is a novel anti-anflammatory agent as well as an anti-proliferative agent due to its 1,2-napthoquinone substructure.