CTGF protein is expressed in the term human placenta. Formalin-fixed sections of normal term human placentas were stained for CTGF (A–C, magnification, ×200; B, bar, 50 μm) and counterstained with hematoxylin. A, No primary antibody control. B, CTGF expression was detected using goat anti-CTGF polyclonal antibody (1:50). C, Control in which the primary antibody was preincubated with a CTGF blocking peptide. D, Syncytiotrophoblast (white arrow) and cytotrophoblast (black arrow). E, Endothelial cells. F, Positive control for CTGF staining of umbilical artery muscularis layer (bar, 100 μm). G, Cultured PHT cells (72 h) stained using anti-CTGF (red) and antidesmosomal (green) antibodies as described in Materials and Methods. White arrows demonstrate CTGF expression in syncytia and in mononucleated cytotrophoblasts (bar, 3 μm). H, Western immunoblotting depicting CTGF protein expression in PHTs cultured in DMEM (D) or Ham’s-Waymouth (H) medium, performed as described in Materials and Methods (n = 3 for each panel).