Primary somatic cells

The process of de-differentiating somatic cells to a pluripotent state whereby they adopt characteristics of embryonnic stem cells is referred to as "cellular reprogramming". This can be achieved through somatic cell nuclear transfer (SCNT), cell fusion with embryonic stem (ES) cells, exposure to stem cell extracts, or by inducing pluripotency mediated by defined factors giving rise to what are termed induced pluripotent stem (iPS) cells.