MAPK8 and dermatitis: Several genes involved in epidermal differentiation, proliferation or formation of the cornified envelope such as Krt25, Krt71, Casp14, Klk5, Tgm3, Klk5, Flg, and histone-encoding genes were down-regulated in absence of JNK1, suggesting that this kinase controls part of the differentiation program induced in the context of skin inflammation.