Some genes upregulated in ICF syndrome patients, such as PTPN13, LHX2, PRRX1, and HHEX, have lower levels of DNA methylation, are enriched in transcriptionally active histone marks and less binding of DNMT3b, and SUZ12 (a component of PRC2 polycomb repression complex), suggesting a connection between DNMT3b and polycomb-mediated repression [155]. Here, DNMT3B is linked to ICF syndrome.