Expressed in salivary glands. Causes an allergic reaction in horses (PubMed:20537727, PubMed:23891138). Binds to IgE in 35% of the 48 Icelandic horses living in Switzerland tested affected by insect bite hypersensitivity (IBH), a recurrent seasonal dermatitis of the horse, caused by bites of Culicoides (midge) and sometimes Simulium (black fly) species. Does not bind to IgE of 27 horses out of the 29 horses living in Switzerland (24 Icelandic, 2 Swiss Warmbloods and 2 Shetland ponies) tested unaffected by IBH. Clear immediate and late phase hypersensitivity reactions to this protein in IBH-affected horses are evident by intradermal skin test (IDT), whereas control horses unaffected by IBH do not develop relevant immediate hypersensitivity reactions (PubMed:20537727). Binds to IgE of 18% of the 167 horses living in Belgium tested affected by IBH. Binds to IgE of 6% of the 176 horses living in Belgium tested not affected by IBH (PubMed:23891138). Belongs to the CRISP family.