Many types of tumors harbor a mutation in the gene for the metabolic enzyme isocitrate dehydrogenase result-ing in the production of the oncometabolite d-2-hydroxy glutarate with a pleiotropic effect on the cell. The paper provides an overview of the latest knowledge of the me-chanism of carcinogenesis, of specific drugs suppressingd-2-hydroxy glutarate production and of the causes of resistance complicating treatment based on specific inhibi-tors of oncogenic forms of isocitate dehydrogenase.