A previous animal experiment concludes that genetic ablation of MKRN3 accelerates the onset of puberty in mice, and the MKRN3/MBD3 axis controls the epigenetic switch of puberty onset in mammals [13], which inspired us to measure MBD3 expression in human sera and to investigate the differential expression pattern of MBD3 in CPP patients and healthy pre-pubertal children and its clinical significance. The gene discussed is MKRN3; the disease is central precocious puberty.