DLK1 and leukemia: Similarly, aberrant imprinting and expression of IGN genes including those from the IGF2-H19 and DLK1-MEG3 loci occurs in leukemias, leading to the hypothesis that very small embryonic-like stem cells (VSELs), as the pluripotent stem cells atop the adult stem cell hierarchy, may adopt a malignant fate along their differentiation route to HSCs via improper epigenetic transitions [3].