IL6 and Alzheimer disease: The associated mechanisms included AD-MSC engraftment; increased circulatory levels of IL-10, TGF-β, and Tregs; suppressed T helper 1 (Th1) and T helper 17 (Th17) cells; decreased circulatory levels of TNF-α, IFN-γ, and IL-6; and reduced graft infiltration of lymphocytes.