Fig. 4

Methylation patterns of sub-group 2 genes in validation sets. A The methylation levels of sub-group 2 genes in normal and ESCC samples in GSE52826 dataset. B The differentially methylated six genes between ESCC and paired normal samples. Paired student t-test was used to estimate significant p values. C The methylation levels of five genes in normal and ESCC samples in TCGA-ESCC. D The differentially methylated four genes between ESCC and normal samples. The Wilcoxon rank sum test was used to estimate significant p values. E ROC curves of the four genes in classifying TCGA-ESCC and normal samples. F–G The identified ESCC-DMRs of HOXC10 and HOXD1 represented by R1–R4 and R1-R7 respectively