Anti-NLGN4 antibodies enable researchers to detect and measure the NLGN4 antigen in biological samples. This target is a reported synonym of the NLGN4X gene, which encodes neuroligin 4 X-linked. This protein is known to function in brain development and chemical synaptic transmission, among other biological roles. The human version of NLGN4 has a canonical amino acid length of 816 residues and a protein mass of 91.9 kilodaltons, although 2 isoforms have been identified. It is reported to be localized in the cell membrane of cells and notably expressed in the cerebral cortex. NLGN4 is a member of the Type-B carboxylesterase/lipase protein family.