Monomer. Homodimer. Highly expressed in foregut (stomach), midgut and hindgut. Not expressed in body wall, reproductive system or body cavity. Causes an allergic reaction in human (PubMed:27069539, PubMed:30894561). Binds to IgE in 29% of the 38 dust mite allergic children tested. 43% of the 98 dust mite allergic adults tested show a positive response to this protein by skin prick test (PubMed:27069539). Binds to IgE in all of the 24 D.farinae allergic patients tested. There is a positive correlation between the number of specific major epitope residues in this allergen and the specific IgE level of the atopic population. The higher the IgE level of the patient for this protein, the higher the number of recognized epitope residues in this allergen by the IgE of the individual out of the 38 determined surface-exposed epitopes tested (PubMed:30894561). Causes an allergic reaction in mice. Mice allergic to this protein display elevated specific IgE and IgG1, increased levels of interferon gamma and interleukin-4 as well as increased proliferation of the spleen cells, airway hyperresponsiveness, large quantity of exudates in the airway lumen and profound inflammatory cell infiltration in the lung tissue (PubMed:27069539). Belongs to the mite group 5 allergen family.