IL1B and Hyperkeratosis: Although the exact role of the ma/ma in the AD-like phenotype is not elucidated, a few studies having used a flaky tail mouse devoid of the matted mutation (flgft/flgft/J), are informative: 8 week old flgft/flgft/J mice have normal TEWL, but present mild orthokeratotic hyperkeratosis and acanthosis, lymphocytic infiltrates in the skin and high Il1β and IlRA mRNA levels (Fallon et al. 2009; Kezic et al. 2012).