Abstract: The present invention relates to isolated and purified Magmas protein, isolated and purified nucleic acids encoding Magmas protein, and antibodies to Magmas protein, which interacts with granulocyte macrophage colony stimulating factor (GM-CSF). More specifically, the invention relates to uses of such anti-Magmas antibodies. The invention further relates to a method for diagnosis, prognosis and treatment of diseases, particularly, cancer, Alzheimer's disease and mitochondrial diseases using Magmas sequences and antibodies directed against the Magmas protein or fragments thereof.