The invention relates to new peptide compounds capable of modulating cell proliferation, differentiation, survival and/or motility. The peptide compounds of the invention comprise short peptide fragments of the ErbB receptor and are capable of binding to ErbB and modulating activity of the receptor. The invention also relates to antibodies capable of binding to an epitope comprising a peptide sequence of the invention, pharmaceutical compositions comprising the peptide sequences and/or antibodies and uses thereof for treatment of conditions wherein modulating activity of ErbB is needed.
