Other uncommon mutations have been identified in the valosin-containing protein (VCP) gene, which cause inclusion body myopathy with Paget disease of bone and FTD (Watts et al., 2004), and in the charged multivesicular body protein 2B (CHMP2B) gene, involved in the endosomal–lysosomal pathway (Skibinski et al., 2005). Here, CHMP2B is linked to bone Paget disease.