The molecular chaperone protein Hsp90 is a key regulator of approximately 100 'client' proteins crucial for numerous cell signaling processes. Consequently, understanding the molecular underpinnings that regulate Hsp90 activity is an important biological endeavor. Exciting new results now suggest that, at least for nuclear receptor activity, Hsp90 function is directly regulated by histone deacetylase 6 (HDAC6). These observations have consequences for various biological processes and potentially important implications for the development of cancer therapeutics.