Immunoglobulin superfamily member 11(IGSF11) is expressed on the plasma membrane in the testis 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 overexpressed 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 the testis and ovary and the IGSF11 can be used as a candidate of cancer-testis antigen.