(S,R)-WT IDH1 Inhibitor 2 (GSK321) is a potent, selective mutant IDH1 inhibitor with IC50 values of 2.9, 3.8, 4.6 and 46 nM for R132G, R132C, R132H and WT IDH1, respectively, and >100-fold selectivity over IDH2. (S,R)-WT IDH1 Inhibitor 2 induces decrease in intracellular 2-HG, abrogation of the myeloid differentiation block and induction of granulocytic differentiation at the level of leukemic blasts and more immature stem-like cells. (S,R)-WT IDH1 Inhibitor 2 can be used for research of acute myeloid leukemia (AML) and other cancers.