Cell reprogramming is an artificial process which changes the state of a cell.
In its normal state, cell gene expression is regulated. Each human body cell contains the same genome although genes are expressed differently depending on the role of the cell (liver cell, heart cell...) and its environmental context (in cell division, attacked by a microbe, etc.).
Cell reprogramming involves changing gene expression, for example, to transform an adult cell into a pluripotent cell.
Cell reprogramming is used to produce stem cells. © Nature Methods