Stem cell self-renewal depends on their ability to divide asymmetrically, with one daughter retaining stem cell identity. This often involves precise orchestration of mitotic spindle orientation, but the machinery used to ensure this outcome is understood in only a handful of examples. In a recent issue of Science, Yamashita et al. provide new insights into the factors that control this process in the male germline of Drosophila, identifying roles for the centrosomal protein Centrosomin and tumor suppressor homologs of the APC family.
