INSL4 (Insulin-Like 4) is a Protein Coding gene. An important paralog of this gene is RLN1. INSL4 encodes a precursor that undergoes post-translational cleavage to produce 3 polypeptide chains, A-C, that form tertiary structures composed of either all three chains or just the A and B chains. INSL4 is a member of the insulin family, which includes insulin, IGF-I, IGF-II, relaxin, and INSL3.INSL4 distribution was tissue- and cell-specific. Indeed, INSL4 mRNA was most abundant in syncytiotrophoblast cells. In fetal tissues, INSL4 mRNA was identified in the perichondrium of all four limbs, vertebrae, and ribs. Diseases associated with INSL4 include Placenta Accreta and Chromosome 9P Deletion Syndrome.