Specially remarkable is the upregulation in HaCaT-IKKα skin equivalents of genes involved in the development of various skin disorders, such as pruritus (KLK5, KLK7; IL1β); dermatitis (BMP6, TNFαIP6); eczema (VNN3, IL1RL1, SPRR2B, SPRR3), psoriasis (CDSN, KLK, LCN2, IL1β), palmoplantar keratoderma (SLURP1; DSC2; DSG1), and ichthyosis (TGM1; ABCA12; ALOX12B, KLK5). The gene discussed is KLK5; the disease is hereditary palmoplantar keratoderma.