IL17A and Hyperkeratosis: The K14-IL17A-ind/+ transgenic mouse represents an animal model of psoriasiform dermatitis characterized by deregulated, persistent overexpression of IL-17A in epidermal keratinocytes leading to prominent development of intraepidermal neutrophil microabscesses in addition to dermal T-cell infiltration, hyperkeratosis, and parakeratosis [23].