Human ELA consists of three exons on chromosome 4,which generates a transcript (AK092578) that is annotated as a non-coding RNA.However,Chng et al.[1] has found that this gene contains a conserved open reading frame predicted to express a conserved vertebrate protein of 54 amino acids (aa) consisting of a secretory signal and a mature 32-aa peptide,which was called as ELABELA (ELA).The sequence of human mature ELA is Gln-Arg-Pro-Val-AsnLeu-Thr-Met-Arg-Arg-Lys-Leu-Arg-Lys-His-Asn-Cys-Leu-Gln-Arg-Arg-Cys-Met-Pro-Leu-His-Ser-Arg-Val-Pro-Phe-Pro.Phylogenetic analysis revealed that the 32-aa mature peptide is evolutionarily highly conserved,with the last 13 residues being nearly invariant in all vertebrate species.ELA has also been previously reported to be highly expressed in undifferentiated human embryonic stem cells (hESCs) and be sharply down-regulated during differentiation [2].