Up: CIN I with morphologic changes related to infection by HPV. Absence of expression of the MoAb BG2 (A) in the basal and parabasal layers, and expressión of this one Ab in the middle of epitelium. Down: Squamous intrapithelial lesion of the high grade. Area of heterogenous expression of MoAb BG6 (Leb) in a CIN III. Focal losses of expression.