Keratin expression in the eye. Mouse specific keratins 14 and 5 (A–J), the acid-base pair, were both expressed in all layers of the corneal epithelium (C,F,I). Keratin 14 was not expressed in the lens epithelium of +/+ (B) or K14HPV18E7 Tg mice (E) while keratin 5 was (H,K). Mouse specific keratin 6 (M–R), a nonspecific marker of epidermal hyperplasia, was expressed in the suprabasal cells of the cornea of both +/+ (O) and K14HPV18E7 Tg mice (R) but not the lens epithelial cells in either group (N,Q).