Nature 523, 352–356 (2015); doi: 10.1038/nature14430

In this Letter on page 353, the words ‘substrate Hsp90’ should have been included in this sentence as follows: “Likewise, histone deacetylase inhibitors, including FDA-approved SAHA, are promising anti-cancer drugs whose actions involve hyperacetylation of histone and select non-histone targets including HDAC6 substrate Hsp90, thus indirectly inhibiting Hsp90 (ref. 21)”. This has been corrected in the online versions.