The invention relates to a novel protein of neutrophils factor Alpha, the protein is a member of the TNF protein family. More particularly, the invention provides some separated nucleic acid moleculars. The codes of the nucleic acid moleculars comprise protein of human neutrophils factor Alpha in the domain of soluble exterior cell structure. The invention also provides polypeptide of the neutrophils factor Alpha, a carrier producing the polypeptide, a host cell and a restructuring method. The invention also relates to a selection method of an agonist and an antagonist distinguishing the activity of the neutrophils factor Aphla. The invention also provides a diagnosing method used for detecting the diseases relating to an immune system and a curing method used for curing the diseases relating to the immune system.
