Our present findings combined with recently reported data [13,14], reinforce and further extend the idea that extracellular chaperoning of both the α and the β isoforms of HSP90, at least in relation to cancer cell invasion and metastasis, is exerted at multiple levels such as activation of growth factor receptor as previously reported[14] and MMP2 and MMP9 activation. Here, HSP90AB1 is linked to cancer.