Other proteins present in the neuroblast mediate the asymmetric localization of Numb and Prospero. This process of neuroblast differentiation via Asc is common to all animals. The daughter cells of a neuroblast have two decidedly different neural fates. Pon binds to Numb and colocalizes with it during neuroblast cell division. Each neuroblast goes on to create a specific sequence of cells with particular identities. A neuroblast lineage can produce as few as 3 GMCs or up to 20. In all, a neuroblast is capable of generating an indefinite number of neurons or glia. In "Drosophila melanogaster", SCRIB is involved in synaptic function, neuroblast differentiation, and epithelial polarization.