ERBB3 and breast cancer: Of interest, ZNF217 was identified as a marker of poor prognosis in breast cancer [36], was shown to drive epithelial-mesenchymal transition and invasion [36], as well as enhance ERBB3 transcription; the latter is required for ERBB2-dependent breast tumor proliferation, since the ERBB2-ERBB3 heterodimer is the functional “oncogenic unit” [37].