Аннотация:Our study demonstrated that leukoplakia as precancer appeared to have differentiation program violations of oral mucosa keratinocytes associated with no specific alterations in immunity. The results suggest that PhM-40 can be used in the treatment of oral leukoplakia. Modulation of keratinocyte differentiation with PhM-40 may be an existing clinical possibility in the control of malignant transformation of oral precancers. In addition, PhM-40 may be considered to be nontoxic immunomodifier.