Selective inhibitor of src family kinases v-Src and c-Fyn as well as the tyrosine kinase c-Abl. (IC50 values are 1.0, 0.6, 0.6, 18 and 22 μM for v-Src, c-Fyn, c-Abl, CDK2 and CAMK II respectively). Preferentially inhibits mutant over wild-type kinases (IC50 values are 1.5 vs 1000 nM for I338G v-src and v-src respectively).