VCP and bone Paget disease: Importantly, mutations in the VCP gene encoding p97 cause the degenerative human disease multisystem proteinopathy 1 (MSP1; also known as inclusion body myopathy associated with Paget’s disease of bone, frontotemporal dementia, and amyotrophic lateral sclerosis, IBMPFD/ALS) [79,80], and pathogenic p97 variants have been reported to affect SG clearance.