NCIt definition : A synthetic, orally bioavailable, small-molecule inhibitor of heat shock protein 90
(Hsp90) with potential antineoplastic activity. Onalespib selectively binds to Hsp90,
thereby inhibiting its chaperone function and promoting the degradation of oncogenic
signaling proteins involved in tumor cell proliferation and survival. Hsp90, a chaperone
protein upregulated in a variety of tumor cells, regulates the folding, stability
and degradation of many oncogenic signaling proteins.;