Fig. 2. Photomicrographs of living cultures (A) and immunoperoxidase preparations of MPC stained for the smooth muscle cell markers calponin (B) and -SMA (C) or the endothelial cell marker FVIII-RA (D). Notice that MPCs are positive for calponin and -SMA, and negative for FVIII-RA. Scale bar, 100 µm.