The invention relates to a polypeptide, wherein said polypeptide comprises or consists of an EGF-like domain of a neuregulin protein. The invention more over relates to a nucleic acid encoding for said polypeptide, a gene therapy vector comprising said nucleic acid and genetically modified cells expressing said polypeptide. The invention relates to the medical use of said polypeptide, said nucleic acid, said gene therapy vector or said cell for the treatment of tumours of the nervous system, in particular for the treatment of tumours of the cranial or peripheral nerves, tumours associated with neurofibromatosis, schwannomas, neurofibromas and malignant nerve sheath tumours.