In the present study, we conducted a follow-up investigation utilizing targeted bisulfite next-generation sequencing (bs-NGS) to analyze leukemic cells from 111 patients with JMML or Noonan syndrome-associated myeloproliferative disorder (MPD) and nine young children without a hematologic malignancy for quantitative DNA methylation at BMP4 as the single gene locus of interest. The gene discussed is BMP4; the disease is myeloproliferative disorder.