The ATPase p97 is an ubiquitin-selective chaperone known to play a critical role in the degradation of misfolded membrane and secretory proteins and has been linked to various cellular processes that require unfolding and disassembly of protein complexes. DBeQ is a selective, reversible, and ATP-competitive inhibitor of the ATPase p97 (Ki = 3.2 μM; IC50 = 1.5 μM). It does not exhibit activity when tested against a panel 170 protein kinases at concentrations as high as 15 μM. At 10 μM it blocks endoplasmic reticulum-associated degradation, impairing the autophagy pathway and promoting the activation of caspase-3 and -7 in cancer cells.