ZSCAN4, a gene expressed in ES cells and 2-cell stage embryos, has been previously shown to regulate telomere elongation and genome stability in mouse ES cells. It is disclosed herein that in the adult human pancreas, a small number of ZSCAN4-positive cells are present among cells located in the islets of Langerhans, acini, and ducts. These data disclosed herein indicates that expression of ZSCAN4 is a marker for rare stem/progenitor cells in adult human pancreas. Thus, provided herein is a method of isolating pancreatic stem cells or progenitor cell from a sample by detecting expression of ZSCAN4. Also provided is a method of treating diabetes by isolating ZSCAN4+ pancreatic stem cells or progenitor cells, expanding the cells in vitro and transplanted the expanded cells into the subject. The expanded ZSCAN4+ cells can optionally be differentiated into pancreatic ß cells before transplanting the cells into the subject. Further provided is an in vivo method of expanding a population of pancreatic stem cells or progenitor cells in a subject by delivering a ZSCAN4 protein, a ZSCAN4 nucleic acid sequence, or an agent that increases expression of ZSCAN4 to the pancreas of the subject.
