Correction to: Nature Chemical Biology, https://doi.org/10.1038/s41589-019-0291-9, published online 27 May 2019.
In the version of the article originally published, an incorrect unit was displayed of the x axis of Fig. 1a. The axis label should read “log10[bortezomib, (mM)]” instead of “log10[bortezomib, (M)]”. The error has been corrected in the PDF and HTML versions of the paper.