Clusterin (CLU) is also known as dimeric acidic glycoprotein (DAG protein), testosterone repressed prostate message-2 (TRPM-2), sulfated glycoprotein-2 (SGP-2) and complement lysis inhibitor (CLI), is a secreted multifunctional glycoprotein protein which belongs to the clusterin family. Intracellular cleavages of the precursor of clusterin remove the signal peptide and generate comparably sized α and β chains which are secreted as an 80 kDa N­glycosylated disulfide­linked heterodimer. DAG protein is predominantly expressed in adult testis, ovary, adrenal gland, liver, heart, and brain and in many epithelial tissues during embryonic development. Clusterin involve in several basic biological events such as cell death, tumor progression, and neurodegenerative disorders. Upregulation of clusterin mRNA and protein levels detected in diverse disease states and in in vitro systems have led to suggestions that it functions in membrane lipid recycling, in apoptotic cell death, and as a stress-induced secreted chaperone protein, amongst others.