AREG and Hyperkeratosis: Concordantly, in Rhbdf2P159L/P159L mice, genetic deletion of Areg restores the normal skin phenotype (Hosur et al., 2017a), suggesting that AREG mediates the hyperplasia, hyperkeratosis, alopecia, and rapid wound-healing phenotypes in Rhbdf2P159L/P159L and Rhbdf2cub/cub mice.