Updated project metadata. Our aim was to identify Regenerating islet-derived (REG proteins in dogs. We annotated REG-family members in the canine genome and proteome, and identified one member of the REG3 subfamily, consequently termed REG3E by the Vertebrate Gene Nomenclature Committee. We verified REG3E gene expression using publicly available RNA-seq data (www.barkbase.org). We investigated the presence of REG3E protein in canine pancreatic tissue and plasma with Western blot and immunohistochemistry, using anti-human REG3A antibodies. Protein identity was subsequently confirmed with mass spectrometry on canine pancreas homogenates and plasma.