Src family kinases are non-receptor tyrosine kinases with diverse roles in signal transduction and disease. A-419259 is an inhibitor of Src family kinases, with IC50 values for Src, Lck, Lyn, and Hck of 9, 3, 3, and 0.43 nM, respectively. It displays at least 1,000-fold selectivity for these enzymes over other kinases. A-419259 induces growth arrest and apoptosis in chronic myelogenous leukemia cell lines. It prevents differentiation while maintaining pluripotency in embryonic stem cells.
