AP5M1 and neoplasm: Strikingly, spindle orientation defective mutants, such as mud (an ortholog of mammalian Numa, which is important for the localization of Dynein/Dynactin motor proteins in spindle orientation), or the cell polarity mutants, scrib and dlg, also lead to the generation of two cellular populations, which, upon blocking cell death, cooperate to promote neoplastic tumour formation [61, 141].