BSG and leukoplakia: The consistent expression of CD147 across dysplasia and carcinoma may be justified by the expected expression of CD147 in the basal cell layer by normal stem cells, due to the self-renewal process. Our findings (higher levels of CD147 expression in OSCC cases and moderately and severely dysplastic leukoplakia than in mildly and non-dysplastic leukoplakia) are in accordance to the relevant bibliography (with the exception of one study, which is of Ueda et al. {2007} [39]), where it was reported that the more CD147 is expressed, the worse the clinical appearance is.