Lipid raft-mediated cargo loading into exosomes. Lipid raft is a membrane domain enriched in cholesterol, sphingolipids, and GPI-anchored proteins. Proteins associated with lipid rafts can be sorted into intralumenal vesicles (ILVs) in multivesicular bodies (MVBs). Shift of membrane proteins in non-lipid raft domain to lipid raft might facilitate their incorporation into ILVs of MVBs. MVBs fuse with the plasma membrane and release exosomes into extracellular space. Disruption of lipid raft by methyl-β-cyclodextrin inhibits the secretion of these proteins through exosomes.