SELP and Hyperkeratosis: We also found that, apart from a remarkable infiltration, >18-month-old P-Sel−/− mice presented hyperproliferation of the epidermal layer (acanthosis), accumulation of keratin in the corneal layer (hyperkeratosis) and keratin plugs inside hair follicles (Fig. 4a, lower panels), described as murine lupus-like lesions32, 33, 34, 35.