DNA methylation is also linked to ENS development because enteric progenitor cells (EPCs) have decreased DNA methyltransferases (DNMT catalyzes the transfer of methyl groups to specific CpG sites in DNA) expression in HSCR patients compared to controls, and some HSCR patients have presumed pathogenic missense mutations in Dnmt3b [122]. Here, DNMT1 is linked to Hirschsprung disease.