Major protein in sweat, has surfactant properties. Has a role in temperature regulation by having a capacity to make hydrophobic surfaces wettable and so can function in promoting spreading and evaporation of sweat. Monomer. Found in sweat (at protein level). No sign of N-X-[ST] acceptor site even though reported as N-glycosylated. Causes an allergic reaction in human. Allergen of horse dander. Belongs to the BPI/LBP/Plunc superfamily. Plunc family.