The charged multivesicular body proteins, commonly designated CHMPs, belong to the vacuolar sorting protein family and function as chromatin-modifying proteins. CHMP1-6 are all components of ESCRT (endosomal sorting complex required for transport) I, II or III complexes. These complexes are crucial for sorting endosomal articles into multivesicular bodies (MVBs), and are also required for the formation of these bodies. CHMP2B, also known as CHMP2.5 or vacuolar protein-sorting-associated protein 2-2, is a 213 amino acid cytosolic protein. Widely expressed in brain, heart, skeletal muscle, small intestine, pancreas, lung, placenta and leukocytes, CHMP2B associates directly with CHMP2A and vps4 for the disassembly of the ESCRT-III complex. Defects in the gene encoding CHMP2B have been shown to cause chromosome 3-linked frontotemporal dementia (FTD3).