The present invention relates to the use of a modulator of a polypeptide having or comprising an amino acid sequence as disclosed herein or of a functional fragment or derivative thereof or of a polynucleotide encoding said polypeptide or fragment or derivative for the preparation of a pharmaceutical composition for preventing, alleviating or treating diseases or conditions associated with the degeneration or injury of vertebrate nervous tissue, associated with seizures or associated with angiogenic disorders or disorders of the cardio-vascular system. Furthermore, the invention provides for the use of a modulator of a polypeptide having or comprising said amino acid sequence of a functional fragment or derivative thereof or of a polynucleotide encoding said polypeptide or fragment or derivative for the preparation of a pharmaceutical composition for preventing, alleviating or treating diseases or conditions associated with the degeneration or injury of vertebrate nervous tissue, associated with angiogenic disorders or disorders of the cardio-vascular system. In addition the invention provides for the use of said polypeptide or said functional fragment or derivative thereof for the preparation of a pharmaceutical composition for preventing or treating tumor growth or formation of tumor metastases or as a marker of stem cells.