{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Survivin, also called baculoviral inhibitor of apoptosis repeat-containing 5 or BIRC5, is a member of the inhibitor of apoptosis (IAP) family. The survivin protein functions to inhibit caspase activation, thereby leading to negative regulation of apoptosis or programmed cell death. The survivin protein is expressed highly in most human tumors and fetal tissue, but is completely absent in terminally differentiated cells."}]},{"type":"paragraph","children":[{"type":"text","value":"Survivin expression is also highly regulated by the cell cycle and is only expressed in the G2-M phase. It is known that survivin localizes to the mitotic spindle by interaction with tubulin during mitosis and may play a contributing role in regulating mitosis."}]},{"type":"paragraph","children":[{"type":"text","value":"The association of survivin expression with tumor progression, but not overall patient survival, has been observed in a variety of malignancies including renal cell carcinoma, ovary carcinoma, hepatocellular carcinoma, prostate carcinoma and breast carcinoma."}]}]}