CTCF and Down syndrome: In the study of M. Reza Sailani et al., DMRs in EP300, E2F6, SMC3 and CEBPB binding sites were highlighted in Down's syndrome twins discordant for AVSD, while for Down's syndrome twins discordant for VSD highlighted POLR2A (polymerase (RNA) II polypeptide A), CTCF and EP300 [140].