Interestingly, VCP inhibitor CB-5083, which increases the K6-linked polyubiquitination, is currently under investigation as an approach to target the ubiquitin proteasome system in different types of hematological and solid malignancies.47,48 These studies collectively support the notion that K6-linked polyubiquitination may serve as an important signal for tumor suppression. This evidence concerns the gene VCP and neoplasm.