Anti-NRT1 antibodies enable researchers to detect and measure the NRT1 antigen in biological samples. This target is a reported synonym of the IGSF9 gene, which encodes immunoglobulin superfamily member 9. This protein is known to function in axon guidance and dendrite development, among other biological roles. The human version of NRT1 has a canonical amino acid length of 1179 residues and a protein mass of 126.6 kilodaltons, although 2 isoforms have been identified. It is reported to be localized in the cell membrane of cells. NRT1 is a member of the Turtle protein family.