NSC305787 hydrochloride is an inhibitor of ezrin with a Kd of 5.85 μM, and has antitumor activity. NSC305787 inhibits PKCΙ phosphorylation of Ezrin, Moesin, Radixin, MBP, with IC50s of 8.3, 9.4, 55, 58.9 μM, respectively. NSC305787 binds to PKCΙ with a Kd value of 172.4 μM, and inhibits ezrin T567 phosphorylation primarily via its binding to ezrin and not through inhibition of PKCΙ kinase activity. NSC305787 (1, 10 μM) shows inhibitory activity against ezrin-mediated invasion of K7M2 osteosarcoma (OS) cells. Moreover, NSC305787 (10 μM) reduces cell motility phenotypes in zebrafish and blocks OS metastatic growth in lung organ culture.