Background: C-terminal binding protein(CtBP)is encoded by two similar genes in the vertebrates,CtBP1 and CtBP2.Both CtBP1 and CtBP2 locate in nucleus and participate in nuclear activities such as transcriptional regulation of gene expression.CtBP1is also found in the cytoplasm and is reported to be involved in the activities of membrane fission.CtBP1 and CtBP2 have important function in embryonic development and loss of CtBP2 associates with embryonic lethality.