Genetically Programmed Differences in Epidermal Host Defense between Psoriasis and Atopic Dermatitis Patients
Figure 2
Two-way clustering of samples and expressed genes.
Cluster analysis was performed on expression levels of 51 genes in 63 samples of cultured keratinocytes from healthy individuals (NS), psoriasis patients (PS) and atopic dermatitis patients (AD). Cells were left untreated (KGM) of stimulated with cytokines (Th1 and Th2). Only those genes that passed the test for false discovery rate (51 out of 55) were included in the analysis. qPCR data were subjected to Z-transformation and the Euclidian distance was used as a dissimilarity measure. Columns and rows were clustered by Ward’s amalgamation rule. Sorting in two dimensions reorganizes the data and generates an expression matrix depicted as a heat-map in which each cell was assigned a color corresponding to its normalized value. Gene clusters on the horizontal axis are numbered (1–2) as described in the text. Clusters of samples on the vertical axis are labeled A–E as described in the text.