Has strong antibacterial activity against P. aeruginosa. Predominates in the parotid glands, present in smaller amounts (1/10) in the submaxillary glands and in the sublingual glands, and at lower amount in the pancreas but undetectable in the liver. Found also in lacrimal gland. Expressed at low levels at day 3 after birth but increased gradually with age from this time. Belongs to the BPI/LBP/Plunc superfamily. Plunc family.