Expression of MUC4 in verruca vulgaris, condyloma acuminatum and vulval hyperplasia. (A,B) MUC4 showed a restrictive expression (25–50% positive cells) with moderately strong staining (intensity 2+) in verruca vulgaris removed from the skin of the abdominal region of a 10-year-old girl. (C,D) Strong cytosolic and membrane staining for MUC4 was observed in a case of squamous hyperplasia of the vulval skin obtained from a 20-year-old woman. (E,F) Strong membrane and cytoplasmic MUC4 expression was also noted in the in condyloma acuminatum of the vulva (representative section from a 27-year-old woman), especially in the koilocytes. (A,C,E) Magnification ×100, and (B,D,F) magnification ×200, to demonstrate subcellular localisation of MUC4; insets, low magnification (×40).