Just recently, Makino et al. checked the HRNR expression by immunostaining in skin lesions from patients affected by hyperkeratosis-associated diseases (ichthyosis vulgaris, epidermolytic ichthyosis (EI), Darier’s disease, lichen planus, pustulosis et plantaris, actinic keratosis and seborrheic keratosis). This evidence concerns the gene HRNR and actinic keratosis.