BPIFA1 and nasopharyngeal carcinoma: Bacterial permeability family member A1 (BPIFA1), also known as short palate and nasal epithelial clone 1 (SPLUNC1), secreted protein from the upper respiratory tract, LUNg-specific protein-X and nasopharyngeal carcinoma-related protein, is a multi-functional protein that is secreted by airway epithelia and has both antimicrobial activity and regulates ion channels9.