FIGURE 2.

Exosome composition: (1) Lipids: lipid bilayers form the exosome membrane (yellow label); (2) nucleic acids: DNA and RNA (mRNA, miRNA) (purple label); (3) immunoregulatory molecules: major histocompatibility complex (MHC): MHC‐I, MHC‐II (orange label); (4) proteins: transmembrane proteins: tetraspanins (CD9, CD63, CD81), adhesion factors: intercellular adhesion molecules (ICAM), integrin, transferrin receptor, flotillin; heat shock protein, cytoskeletal protein, metabolic enzymes, signal transducers (blue label); (5) metabolites: derived from maternal cells and the surrounding microenvironment, such as amino acids (green label).