Apoptozole is an inhibitor of Hsc70 and Hsp70, which binds to Hsc70 and Hsp70, with Kds of 0.21 and 0.14 μM, respectively. Apoptozole (Apoptosis Activator VII; 1 μM) induces apoptosis in P19 cells. Apoptozole shows inhibitory activities against several cancer cell lines, such as SK-OV-3 (ovarian cancer cells), HCT-15 (colon cancer cells), and A549 (lung cancer cells), with IC50s of 0.22, 0.25, and 0.13 μM, respectively. Apoptozole binds to the ATPase domain of Hsc70 and Hsp70, but does not binds to other types of heat shock proteins such as Hsp60, Hsp90 or Hsp40. Apoptozole (0-15 μM) suppresses the growth of A549 cells, HeLa cells, and MDA-MB-231 cells, with IC50s ranging from 5 to 7 μM. Apoptozole (5 or 10 μM) shows no effect on associations of HSP70 with ASK1, JNK, or BAX, and does not induce AIF-mediated caspase-independent apoptosis in HeLa cells.