HSP90AA1 and fibrosarcoma: The ability of SST0116CL1 to target Hsp90 directly on human tumor cells was evaluated by a tumor cell proliferation assay against a representative panel of human tumor cell lines, including fibrosarcoma (HT-1080), acute monocytic leukemia (MV4;11), NSCLC (NCI-H460), ovarian (A2780), epidermoid (A431), gastric (GTL-16), breast (BT-474) carcinoma cell lines, characterized by constitutively activated oncogenic pathways (Table II).