LYZ and dental caries: Lysozyme is an important antibacterial component that is extensively present in mammalian serum, liver, secretions (i.e., saliva, tears, urine, and milk), and immune cells, and on mucosal surfaces.9,10 It has an antimicrobial effect via selective decomposition of the cell walls of microorganisms, with no destruction of other tissues.11,12 As the cornerstone of innate immunity, lysozyme is involved in the homeostasis of the oral environment, the disruption of which is related to the occurrence and development of dental caries,13 oral mucosal disease,14,15 and periodontal disease.16