For example, to identify binders of eHsp90 we used mass spectrometry analysis of Hsp90 alpha immunoprecipitation from MB-231 breast cancer cell conditioned media to identify a pro-form of tissue plasminogen activator (TPA) and then showed that active TPA could rescue eHsp90 inhibition-mediated loss of cell migration [10]. The gene discussed is PLAT; the disease is breast cancer.