genomic DNA was extracted from the collected tissue samples using the QIAamp DNA Mini Kit (Qiagen, Hilden, Germany). as outlined in the manufacturer's recommendations and guideline. After DNA extraction, the DNA concentration and purity were assessed using Nanodrop (Thermo Fisher, Carlsbad, CA, US). A total 500ng of genomic DNA was fragmented using M220 Focused-ultrasonicator (Covaris, Woburn, MA, US) with low-EDTA TE buffer. The quality, quantity, and fragment size (major peak in 250–300 bp) of sheared genomic DNA was verified using a 2100 Bioanalyzer system (Agilent Technologies, Santa Clara, CA, USA) prior to library preparation. The DNA library was bisulfite-converted using the EZ DNA Methylation-Gold™ Kit (Zymo Research, Irvine, CA, USA). Then, the library was prepared using the Accel-NGS® Methyl-Seq DNA library kit (Swift Biosciences, Ann Arbor, MI, USA) and other specified enzymes, buffers, and reagents in manufacturer's protocol. Finally, 8 libraries were pooled and incubated with probe pool designed for targeting the regions of our interest. After clean-up, the libraries were sequenced on HiSeq2500 sequencer (Illumina, San Diego, CA, US) with 2 X 100bp pair-end reads with unique dual index and generated 2Gb of sequencing data from each sample.