(June 21, 2009) - Notch signaling helps determine the fate of a number of different cell types in a variety of organisms, including humans. In an article that appears in the current issue of Nature Cell Biology, researchers at Baylor College of Medicine report that a new finding about the Notch signaling pathway in sensory organ precursor cells in the fruit fly could explain the mystery behind an immunological disorder called Wiskott-Aldrich syndrome.