Conceptual illustration of mitochondrial morphology changes during cellular reprogramming. Mitochondria (blue and green ovoids) are organelles that provide energy to the cell. Cellular reprogramming is the process of reverting mature differentiated cells to pluripotent stem cells, that is cells that can develop into any of the cell types in the human body. Differentiated cells have an elongated mitochondrial network, while pluripotent cells have a fragmented mitochondrial network.