ERBB3 and breast cancer: In fact, the erbB2/erbB3 heterodimer has been identified as the most potent form of all erbB receptor complexes to activate the oncogenic signaling, such as PI-3 K/protein kinase B (Akt), mitogen-activated protein kinase kinase (MEK)/mitogen-activated protein kinase (MAPK), and/or janus kinase (Jak)/signal transducer and activator of transcription (Stat) pathways, and/or Src kinase, in breast cancers [17-19].