Anti-CAS antibodies enable researchers to detect and measure the CAS antigen in biological samples. This target is a reported synonym of the CSE1L gene, which encodes chromosome segregation 1 like. The human version of CAS has a canonical amino acid length of 971 residues and a protein mass of 110.4 kilodaltons, although 4 isoforms have been identified. It is reported to be localized in the nucleus and cytoplasm of cells and notably expressed in the testis, placenta, nasopharynx, and fallopian tube. CAS is a member of the XPO2/CSE1 protein family.