Figure 1
From: CTCF as a multifunctional protein in genome regulation and gene expression
H19 and Igf2 gene expression is controlled by CTCF binding at the ICR. CTCF fails to bind to the methylated paternal ICR; thus, the enhancer (E) can induce Igf2 gene expression. However, CTCF binding to the unmethylated maternal ICR acts as a barricade between the Igf2 gene and the enhancer, activating H19 gene expression. CTCF, CCCTC-binding factor; ICR, imprinting control region.
