Maternal-specific H19-DMR deletion results in activation of the Igf2-Igfr1 pathway, as shown by the translocation of phosphorylated FoxO3 (an inactive form) from nucleus to cytoplasm and the release of FoxO3-mediated cell cycle arrest, thus leading to increased activation, proliferation and eventual exhaustion of haematopoietic stem cells.     ///    "We demonstrate that conditional deletion of the maternal but not the paternal H19-DMR reduces adult haematopoietic stem cell quiescence, a state required for long-term maintenance of haematopoietic stem cells, and compromises haematopoietic stem cell function. "    ///    "Similarly, genetic inactivation of Igf1r partly rescues the H19-DMR deletion phenotype. "    ///    "Mechanistically, maternal-specific H19-DMR deletion leads to Igf2 upregulation and increased translation of Igf1r, which is normally suppressed by H19-derived miR-675. "    ///    "A differentially methylated region upstream of H19 (H19-DMR), serving as the imprinting control region, determines the reciprocal expression of H19 from the maternal allele and Igf2 from the paternal allele. "