I koncentrationer på 10 µM hæmmer bortezomib ikke nogen af en lang række screenede receptorer og proteaser og er mere end 1500 gange så selektivt for proteasom end for det næste foretrukne enzym.
At 10 μ M concentrations, bortezomib does not inhibit any of a wide variety of receptors and proteases screened and is more than 1500-fold more selective for the proteasome than for its next preferable enzyme.