GNF-6 (Compound 14) inhibits the gatekeeper threonine residue mutation of BCR-ABL-T315I with IC 50 s of 0.25 μM, 0.09 μM and 0.590 μM for c-ABL-T334I, BCR-ABL and BCR-ABL-T315I variants, respectively. GNF-6, an ATP competitive inhibitor, disrupts the assembly of the hydrophobic spine (a network of hydrophobic interactions), thereby locking the kinase in an inactive ‘DFG-out’ conformation.