Once committed to becoming a specific tissue, cells generally cannot go back to more a youthful embryonic state and become other types of cells. However, the video shows what happens after Yale scientists added four genetic factors into blood cells. The cells eventually forms a colony of pluripotent cells, which are capable of becoming many different types of cells. This reprogramming process holds the promise of creating cell-based therapy for a host of serious diseases. A new Yale study identifies a mechanism that makes it easier for individual cells to become young again.