This gene encodes a member of the peroxidase superfamily of enzymes that is produced by eosinophils and plays a critical role in eliminating tissue-invasive parasites. The encoded preproprotein undergoes proteolytic processing to generate a heterodimeric enzyme that forms a predominant component of the intracellular granules of eosinophils. Mice lacking the encoded protein exhibit resistance to ulcerative colitis induced by dextran sulfate. [provided by RefSeq, Jul 2016]