<p>NHEK were cultured in the presence or absence of 10/ml of IL-1α, IL-17A, IL-22, OSM and TNFα alone or in combination for 24 h. Quantitative RT-PCR analysis was carried out on total RNA from 4 independent NHEK cultures. mRNA expression levels for cytokeratin 10 (CK10), cytokeratin 1 (CK1), desmoglein 1 (DSG1), desmocollin 1 (DSC1), fatty acid binding protein 5 (FABP5), calmodulin-like skin protein (CLSP), loricrin (LOR) and filaggrin (FLG) were normalized using GAPDH housekeeping gene and expressed as the fold decrease under unstimulated cultures. (A) Comparison of the activity of IL-1α, IL-17A, IL-22, OSM and TNFα alone or in combination (M5) on expression of keratinocyte differentiation markers. (B) Comparison of the activity of mix of 4 cytokines versus mix of 5 cytokines (M5) on expression of keratinocyte differentiation markers. All data are represented as mean and SEM of 4 independent experiments. One-way ANOVA with a Dunnett post-test were used for statistical evaluation and p values were as follows: *p<0.05, **p<0.01, ***p<0.001.</p