The relaxin-like peptide family belongs in the insulin superfamily and consists of 7 peptides of high structural but low sequence similarity; relaxin-1 (RLN1), 2 (RLN2) and 3 (RLN3), and the insulin-like (INSL) peptides, INSL3, INSL4, INSL5 and INSL6.
A familia de péptidos similares á relaxina pertence á superfamilia da insulina e consta de 7 péptidos de gran semellanza estrutural pero baixa semellanza secuencial, que son as relaxinas 1 (RLN1), 2 (RLN2) e 3 (RLN3), e os péptidos similares á insulina (INSL), INSL3, INSL4, INSL5 e INSL6.