Survivin is a member of the inhibitor of apoptosis (IAP) gene family which counteracts apoptosis by inhibiting the activity of initiator and effector caspases. Survivin associates with the microtubules in the mitotic spindle and antagonizes mitochondrial-dependent apoptosis. In addition to cell death regulation, survivin has also been shown to be important in cell division and its expression is controlled at the transcriptional level in a cell cycle dependent manner. Results aid in the classification of a wide variety of neoplasms including tumors of the lung, breast, colon, stomach, esophagus, pancreas, liver, uterus, ovaries, Hodgkins disease, non-Hodgkins lymphoma, leukemias, neuroblastoma, phaeochromocytoma, soft-tissue sarcoma, gliomas and melanomas. The cellular localization of survivin is nuclear and/or cytoplasmic.