Exosome complexes in a cell, illustration. Exosomes are multi-protein complexes that function to break up strands of RNA (ribonucleic acid, green) during biochemical processes in cells. This is shown here inside a single cell (spherical), with the interior shown in cutaway view. The exosomes have protein subunits that are ribonucleases, enzymes that degrade RNA. The cell membrane is shown with surface proteins.