Comparison of gene expression in fibroblasts and keratinocytes. (a-b) Scatter plot of dermal fibroblasts and keratinocytes RNA-seq mRNA expression (reads per kilobase per million mapped reads, RPKM) for (a) fibroblasts specific S1 class and (b) keratinocyte specific S1 class of hypomethylated regions (HMRs) that have TSS within 1-kbp. (c-d) UCSC genome browser screen shots as examples for genes in different group of HMRs, with mRNA expression, methylation status. (c) Specific HMR (S1) leading to different expression at isoform level, example of Trp63 in keratinocytes. (d) Fat1 with high CG methylation at the annotated promoter region with expression in both cells, but have HMRs and RNA-seq signals at approximately 15 Kb upstream.