We found 25 proteins with altered expression levels in saliva from OSCC patients (see Table 2), some of which, like phosphoglycerate mutase, glutathione S-transferase, retinoic acid binding protein II, cofilin, galectin-7 and C-reactive protein, have been already described in cancer cell lines [37, 38] but not in the saliva of OSCC patients. This evidence concerns the gene HPGDS and cancer.