Apparent precursor of a secreted, cationic, proline- and cysteine-rich peptide that contains Cys-Pro-Xaa repeats (PubMed:2351676). Unlike cryptdin, the proposed mature peptide region lacks the structural motif characteristic of defensins (PubMed:2351676). Small bowel. Accumulates to high levels in intestinal crypt epithelium from 14 days of age to 40 days of age. Belongs to the alpha-defensin family.