A novel isolated and purified human protein inhibitor of apoptosis, termed livin, is described. A cDNA sequence which encodes the native inhibitor of apoptosis (livin) is disclosed as well as the structural coding region and the amino acid residue sequence. Molecular sequences are provided for the design and synthesis of entities that modulate biological and/or pharmacological activity of the native biomolecule. Methods are provided which employ the sequences to identify compounds that modulate biological and/or pharmacological activity of the native biomolecule. Biologically-effective antisense molecules as well as dominant negative mutant versions of the livin protein which are suitable for therapeutic are also provided. The invention is also drawn toward the study, prevention, diagnosis, and treatment of pathophysiological disorders related to apoptosis.