In August 2008, Melton's lab published successful in vivo reprogramming of adult mice exocrine pancreatic cells into insulin secreting cells which closely resembled endogenous islet beta cells of the pancreas in terms of their size, shape, ultrastructure, and essential marker genes.[14] Unlike producing beta cells from conventional embryonic stem cells or the more recently developed induced pluripotent stem cell (iPSC) technique, Melton's method involved direct cell reprogramming of an adult cell type (exocrine cell) into other adult cell type (beta cell) without reversion to a pluripotent stem cell state.