Species-specific MHC analyses. (A, B): Immunohistochemical staining of human- (A) or rat-specific (B) MHC. (C, D): Quantifications for osteoblasts (C) and osteocytes per higher power field (D). Blue scale bar = 100 μm. ∗, p ≤ .05 compared with rat-specific control values; ∗∗, p ≤ .01 compared with rat-specific control values; ##, p ≤ .01 compared with human-specific control values. A significant dose-dependent effect was observed between hPSC-treated groups. Abbreviations: hMHC, human-specific major histocompatibility complex; HPF, higher power field; hPSC, human perivascular stem cells; MHC, major histocompatibility complex; Ob, osteoblasts; Ot, osteocytes; rMHC, rat-specific major histocompatibility complex.