The transcriptome of the aging human epidermis. (A) MA plot showing fold change between young and old in relationship to the mean expression level. Red marks indicate genes with significant differential expression, as determined by DESeq analysis. (B) Venn diagram showing the overlap in differentially expressed gene sets, as determined by DESeq (green) and by Cuffdiff 2 (orange). (C) Connective Tissue Growth Factor (CTGF) is shown as a representative example for a differentially expressed gene. RNA-seq coverage is indicated for young (blue) and old (red) samples. (D) Ingenuity pathway analysis of differentially expressed genes. The plot shows the four most significantly enriched functional categories.