VCP p97 inhibitor-1, a highly effective compound, inhibits VCP p97 (also known as Cdc48, CDC-48, or Ter94) with an IC 50 of 54.7 nM. This inhibitor induces a disruption in protein homeostasis and interferes with the degradation process of misfolded polypeptides by the ubiquitin-proteasome system (UPS).