A-C. 2.5x105 of TGF-β1 siRNA or control siRNA transfected AT-MSCs were intradermally injected around each of CD18-/- murine wound. PBS mock injection served as negative control. Wound tissue were harvested at day 2, 5, and 7 post-wounding for quantification of human TGF-β1 mRNA (A) at day 2 by qPCR, total TGF-β1 (B) and active TGF-β1 (C) protein at day 5 by ELISA. 