TGFB1 and Alzheimer disease: Recent exploration of immunomodulation showed that AD-MSC surface-bound glycoprotein A repetitions predomain/leucine-rich repeat containing-32 (GARP/LRRC32), found on CD4+/Foxp3+ Tregs, megakaryocytes, and platelets, binds to membrane-bound TGF-β1, holding it in an inactivated but readily-accessible state.