A partially-selective, cell permeable DUB inhibitor that directly inhibits USP9x, USP5, USP14, and UCH37. WP1130, derived from the tyrphostin AG490, was identified in a screen for molecules that suppress IL-3 and IL-6 activation of STAT molecules. It has been subsequently shown to induce rapid accumulation of polyubiquitinated (K48/K63-linked) proteins into juxtanuclear aggresomes, block JAK2 signaling through JAK2 ubiquitination and subsequent downregulation, and exhibit antiviral activity through activation of the unfolded protein response (UPR). Typical concentration for cell culture experiments is 5 μM.