Representative immunohistochemical analysis for CTGF/CCN2 protein expression (A) shows the extracellular (asterisk) and intracellular (arrows) CTGF in deep connective tissue (DCT) in phenytoin (PHE) and human gingival fibromatosis (HGF) samples and not in controls. Epithelium (Ep) of fibrotic lesions stained for CTGF/CCN2 in PHE and HGF samples. Both gingival fibrosis lesions exhibited elongated rete pegs. Non-immune IgG stained serial sections showed no CTGF/CCN2 staining. Measure bars represent 200 μm at a magnification of 200×. (B); quantitative analyses of fibrosis, inflammation, and CTGF expression in connective tissue stroma are means +/− SE, (*, p<0.05), n = 12, PHE; n = 9, HGF; n = 12, no overgrowth controls.