Anti-X5L antibodies enable researchers to detect and measure the X5L antigen in biological samples. This target is a reported synonym of the FAM50B gene, which encodes family with sequence similarity 50 member B. This protein is known to function in chromatin organization, among other biological roles. The human version of X5L has a canonical amino acid length of 325 residues and a protein mass of 38.7 kilodaltons. It is reported to be notably expressed in many tissues, such as the cerebral cortex, thyroid gland, and caudate. X5L is a member of the FAM50 protein family.