Fig. 1

Selection of cell type-specific CpGs for fibroblasts. a Multidimensional scaling (MDS) plot of the training data set (n = 409) demonstrates that samples cluster by cell type across different studies. All CpGs shared between the 450K and EPIC BeadChip were considered (except XY chromosomes). b Differential mean DNAm levels of fibroblasts/MSCs versus all other cell types were plotted against the sum of variances within both groups. The CpGs, which have been selected for the FibroScore, are indicated. c DNAm levels (β values) of the two selected CpGs of the FibroScore in the training set. Numbers correspond to classification accuracy in percentage values. d DNAm levels of the two selected CpGs and the FibroScore for the validation set. Only muscle stem cells, which might closely resemble MSCs, were classified with fibroblasts/MSCs. Numbers correspond to classification accuracy in percentage values. e DNAm levels of the two selected CpGs and the FibroScore as determined by pyrosequencing in samples of different cell types. Almost all cell preparations (with exception of the HaCat cell line) were classified correctly. f The FibroScore is significantly higher in lung fibrosis versus healthy control tissue (GSE63704; 450K data) [62]. ***p < 0.001. g The FibroScore is significantly higher in liver cirrhosis versus healthy control tissue (GSE60753; 450K data) [29]. *p < 0.05