HSP90AB1 and cancer: In addition to the epichaperome’s presence in the cytoplasm of tumor cells, recent studies indicate that the chaperone cluster (including members of the HSP70 and HSP90 families) is also present on the surface of the plasma membrane, likely forming a functional epichaperome complex, with inhibitory analysis revealing its involvement in cancer cell invasion and migration in brain tumors (including primary glioblastomas from adult neuro-oncological patients) [52,53].