PTEN and lip and oral cavity carcinoma: The overall goal of this study was to assess the utility of the DJ-1, PTEN, and p-Akt as prognostic indicators in the progression of OSCC via the analysis of cellular protein expression across several cell lines representing normal gingival keratinocytes (PKG), dysplastic oral keratinocytes (DOK), locally invasive oral cancer (SCC25), and metastatic oral cancer (Detroit 562).