NCIt definition : A benzoquinone antineoplastic antibiotic isolated from the bacterium Streptomyces
hygroscopicus. Herbimycin binds to and inhibits the cytosolic chaperone functions
of heat shock protein 90 (HSP90). HSP90 maintains the stability and functional shape
of many oncogenic signaling proteins; the inhibition of HSP90 promotes the proteasomal
degradation of oncogenic signaling proteins that may be over-expressed or overactive
in tumor cells. (NCI04);