Anti-insulin like 3 antibodies are used in the immunodetection of the protein encoded by the INSL3 gene. In humans, the canonical protein has a reported length of 131 amino acid residues and a mass of 14.5 kDa. It is known to be a secreted protein. Alternative splicing is reported to yield 2 different isoforms for this protein. It is reported to be expressed in prenatal and postnatal Leydig cells. A member of the Insulin protein family, it is believed to play a role in testicular function. Other names for this target antigen include RLNL, ley-I-L, insulin-like 3 (Leydig cell), leydig insulin -like hormone, leydig insulin-like peptide, and RLF.