NSC305787 hydrochloride is an inhibitor of ezrin with a K d of 5.85 μM, and has antitumor activity. It inhibits PKCΙ phosphorylation of Ezrin, Moesin, Radixin, MBP, with IC 50 s of 8.3, 9.4, 55, 58.9 μM, respectively. It binds to PKCΙ with a K d value of 172.4 μM, and inhibits ezrin T567 phosphorylation primarily via its binding to ezrin and not through inhibition of PKCI kinase activity. It (1, 10 μM) shows inhibitory activity against ezrin-mediated invasion of K7M2 osteosarcoma (OS) cells. Moreover, it reduces cell motility phenotypes in zebrafish and blocks OS metastatic growth in lung organ culture.