CKLF-like MARVEL transmembrane domain-containing protein 2 (i.e. CMTM2), previously termed chemokine-like factor superfamily 2 ( i.e. CKLFSF2), is a member of the CKLF-like MARVEL transmembrane domain-containing family (CMTM) of proteins. In humans, it is encoded by the CMTM2 gene located in band 22 on the long (i.e. "q") arm of chromosome 16. CMTM2 protein is expressed in the bone marrow and various circulating blood cells. It is also highly expressed in testicular tissues: The CMTM2 gene and CMTM2 protein, it is suggested, may play an important role in testicular development.