We have previously shown that, in Drosophila eye-antennal discs, oncogenic Ras (RasV12) or Raf (Rafgof) can cooperate with mutants that disrupt cell polarity, including scrib, dlg or lgl, to induce tumor invasion and metastasis (Pagliarini and Xu, 2003). The gene discussed is SCRIB; the disease is neoplasm.