By dividing asymmetrically, stem cells maintain their numbers and to generate differentiated daughter cells. In this work, we aim to answer fundamental questions on the regulation and mechanisms of asymmetric stem cell division. We address In particular how asymmetric stem cell division is influenced by external signals, such as those provided by stem cell niches. Using asymmetric exposure of single stem cells to a Wnt protein, we have discovered that the Wnt signal governs both stem cell fate and orientation of division simultaneously. We are now extending this work to include human stem cells, those of epidermal origin and embryonic stem cells. We have designed experiments to elucidate the mechanism of asymmetric stem cell division.