[Ethymisole: reassessing and old drug].

Ethymisole, or 4,5-di(N-methylcarbamoyl)-1-ethyl-imidazole, is a cognitive enhancer and nootropic drug, the molecular target of which is a multifunctional protein kinase C K2 (casein kinase II). New data about signal pathways and protein substrates of CK2 have been obtained due to research effort of many laboratories. The paper presents a historical sketch of molecular investigations underlying memory enhancer effects of ethymisole; this and the other pharmacological effects of ethymisole are considered in the light of new data.