The evolution of pro-opiomelanocortin: Looking for the invertebrate fingerprints

► Pro-opiomelanocortin (POMC)-derived peptides are involved in neuro endocrine functions in all vertebrates. ► POMC-derived and POMC-like peptides are present in invertebrate taxa. ► Discrepancies exist between POMC distribution and phylogeny of metazoans. ► The evolution of POMC-derived molecules remains open to debate.