Inhibition of either fibronectin secretion or tubulin microtubule assembly has been linked to suppression of adhesion52, apoptosis53–55, metastases56,57 and proliferation54 of tumor cells, and we therefore hypothesized that Hsp90 maintains the homeostasis of the microtubule network that provide the framework for trafficking of secretory vesicles. The gene discussed is FN1; the disease is neoplasm.