Defensins are a class of cationic peptides which is widely found in plants and animals, and are a representative sub-clan of antimicrobial peptides family（Antimicrobial peptides are a kind of short-chain peptide of broad-spectrum antimicrobial effects） and a very conservative host defense molecules. So far, a variety of defensins have been found. Human beta defensin（hBD）play an important role in these defensins, and have a strong bactericidal activity, chemotactic activity, regulatory function of phagocytic cells and acquired immune etc. In addition, several researches also found that hBD have an anti-tumor activity, and are closely related with oral carcinoma. Therefore, hBD may provide a new strategy for the prevention and treatment of the tumor.
