IDH2 and central nervous system cancer: In 2013, AGI-5198, the first published inhibitor of mutant IDH1 enzyme, and AGI-6780, the first published inhibitor of the mutant IDH2 enzyme, were shown to be effective against glioma and leukemia cells in vitro [30,31] Inhibition of 2-HG accumulation by these molecules induced differentiation of tumor cells and slowed down the in vivo tumor growth.