Physorg.com -- Stem cell therapies hold increasing promise as a cure for multiple diseases. But the massive potential of a healthy stem cell has a flip side, as faulty regulation of stem cells leads to a huge range of human diseases. Even before birth, mistakes made by the stem cells of the foetus are a major cause of congenital defects, and cancer is also caused by the body losing control of stem cell function. Guiding stem cells along the correct pathways and, where necessary, reversing their mistakes is the goal of everyone in this field.