These results provide evidence that reduced PHLDA1 expression might be important in breast cancer progression as well as in the modulation of oncogenic ErbB2 signaling and should call for more detailed studies of PHLDA1 expression to assess if it could serve as a useful prognostic marker of disease outcome and whether PHLDA1 expression might be lost in particular subsets of tumors. The gene discussed is PHLDA1; the disease is breast carcinoma.