In investigating cooperation between polarity loss and oncogenic pathways in epithelial tumorigenesis, we discovered that activation of the small GTPase, Ras (Ras85DV12, referred to as RasACT herein) or activated Notch (NotchICD, referred to as NotchACT herein) cooperated with scrib loss-of-function to form massive invasive tumours (Brumby and Richardson, 2003). The gene discussed is SCRIB; the disease is neoplasm.