Ca2+ flux across the inner mitochondrial membrane regulates cell bioenergetics, cytoplasmic Ca2+ signals and activation of cell death pathways. Ca2+ uptake from the cytoplasm is driven by the electrochemical gradient... Most healthy cells rely on a complicated process to produce the fuel ATP. Knowing how ATP is produced by the cell's energy storehouse – the mitochondria -- is important for understanding a cell's normal state, as well as what happens when things go wrong, for example in cancer, cardiovascular disease, neurodegeneration, and many rare disorders of the mitochondria.

This is an image of an aged stem cell after growth factors were added. A new method of growing cardiac tissue is teaching old stem cells new tricks. The discovery, which transforms aged stem cells into cells that function like much younger ones, may one day enable scientists to grow cardiac patches for damaged or diseased hearts from a patient's own stem cells—no matter what age the patient—while avoiding the threat of rejection.