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