Potent and selective c-Src inhibitor (Ki = 44 nM); does not inhibit c-Abl at concentrations up to 125 μM. Selective between Src family members (Kd values are 86, 160, 240, 720, 3200, 4400, and >40,000 nM for c-Src, Lck, Fgr, Yes, Lyn, Hck and Fyn respectively). Significantly inhibits cell growth in 4T1 mammary carcinoma tumor cells. Purity 98%. MW (observed): 555.03