The present invention provides a human eosinophil-derived basic protein (EBPH) and polynucleotides which identify and encode EBPH. The invention also provides genetically engineered expression vectors and host cells comprising the nucleic acid sequences encoding EBPH and a method for producing EBPH. The invention also provides for use of EBPH and agonists, antibodies or antagonists specifically binding EBPH, in the prevention and treatment of diseases associated with expression of EBPH. Additionally, the invention provides for the use of antisense molecules to polynucleotides encoding EBPH for the treatment of diseases associated with the expression of EBPH. The invention also provides diagnostic assays which utilize the polynucleotide, or fragments or the complement thereof, and antibodies specifically binding EBPH.