The protein encoded by this gene appears to be involved in several basic biological events such as cell death, tumor progression, and neurodegenerative disorders. However, the function of this protein is unknown. Three transcript variants encoding different isoforms have been found for this gene, and one of them is secreted and processed into a mature form.Synonyms: 40, 40, AAG4, APOJ, Aging-associated gene 4 protein, CLI, Clusterin, Complement cytolysis inhibitor, Complement-associated protein SP-40, KUB1, Ku70-binding protein 1, NA1/NA2, SP-40, Testosterone-repressed prostate message 2