Abstract: CD317 (Tetherin, BST-2 or HM1.24), encoded by the BST-2 gene, is a type II transmembrane glycoprotein with a unique topology. CD317 is constitutively expressed in a variety of human tissues, and can also be induced by some cytokines such as interferon. Recently, many studies have shown that CD317 is overexpressed in different types of tumors with critical roles to facilitate tumor progression by regulating multiple biological processes, such as proliferation, migration and apoptosis. Therefore, CD317 is suggested as a promising target for tumor therapy. This review focuses on the research progress of CD317 in tumor development, including its expression within tumors, mechanisms for tumorigenesis, and potential as a target against cancer, and will hopefully provide novel ideas and direction for discovering tumorigenesis is overexpressed in different types of tumors with critical roles to facilitate tumor progression by regulating multiple biological processes, such as proliferation, migration and apoptosis. Therefore, CD317 is suggested as a promising target for tumor therapy. This review focuses on the research progress of CD317 in tumor development, including its expression within tumors, mechanisms for tumorigenesis, and potential as a target against cancer, and will hopefully provide novel ideas and direction for discovering tumorigenesis mechanisms and new therapeutic strategies.