pMEXs are enriched for specific functional classifications of proteins. (A, C) IPA determined that pMEXs contain elevated fractions of transporters, peptidases, receptors, G-coupled receptors, and ion channels compared with pMSCs. pMEX contained lower fractions of transcription, kinase activity, translation, and phosphatase proteins compared with pMSCs. Proteins exclusively detected in pMSCs (B) contained elevated fractions of enzymes and transcription-associated proteins than proteins detected exclusively in pMEX. (D) Proteins exclusively detected in pMEX contained higher fractions of transporters and G-coupled receptors. n = 3/group, FDR 1%. Red highlight = higher fraction in pMEX, blue highlight = lower fraction in pMEX. IPA, Ingenuity Pathway Analysis.