Immunoglobulin superfamily member 11(IGSF11) are expressed on the plasma membrane in the tesis and brain. These IGSF proteins undergo final modifications during capacitation and/or the acrosome reaction. IGSF proteins share significant homology with endothelial cell-selective adhesion molecule and coxsackievirus and adenovirus receptor, which mediates cell attachment and homotypic intercellular interactions. In clinical, the IGSF11 has been reported to over expressed in colorectal cancers and hepatocellular carcinomas as well as intestinal-type gastric cancers compared to their corresponding non- cancerous tissues. The IGSF11 has also been found expressed abundantly in testis and ovary and the IGSF11 can be used as a candidate of cancer-testis antigen.