Erbb2 interacting protein, also known as erbin, is a protein which in humans is encoded by the ERBB2IPgene. Discovered in 1997, erbin is a 200kDa protein containing a PDZ domain.
Erbin's C-terminal PDZ domain is able to bind to ErbB2, a protein tyrosine kinase which is often associated with poor prognosis in epidermal oncogenesis. Erbin's N-terminalregion has been shown to disrupt Ras to Raf binding and may be, through this action, a tumor suppressing protein.