FN1 and neoplasm: As secretion of FN1 has been implicated as a key mediator of tumor cell invasion and migration, and we found Hsp90 inhibition to suppress FN1 secretion and tumor cell invasion (Fig. 2D), a Matrigel invasion assay was employed in PC-3 cells to compare the effects of AUY922 to (a) siRNA knockdown of FN1 causing depletion of cellular and secreted FN1, or (b) inhibition of FN1 polymerization and ECM fibril deposition using the inhibitory peptide pUR424.