Part of the insoluble cornified cell envelope (CE) of stratified squamous epithelia. Directly or indirectly cross-linked to CE proteins loricin and involucrin (IVL). Constituent of the scaffolding of the cornified envelope. Abundant in the cervix. Moderately abundant in the uterus and fetal skin. Expression is markedly increased in psoriatic skin (18.5 fold increase in comparison with normal skin) and its overexpression alters the protein composition of cornified cell envelope (CE), but does not affect keratinocyte differentiation. Expressed in the granular cell layer of epidermis in uninvolved psoriatic skin and in the psoriatic lesions it is found in the upper-spinous layer. Increased expression also seen in atopic dermatitis (14.3 fold increase in comparison with normal skin) and mycosis fungoides (4.6 fold increase in comparison with normal skin) and in both conditions expressed in the granular cell layer of epidermis. Belongs to the cornifelin family.