RASSF1 and cervical carcinoma: Based on optimal cut-off values, we found OPSCC-specific promoter methylation of AGTR1, DAPK, FHIT, TIMP3 and VGF. Among the analyzed genes, promoter methylation of RASSF1A is less frequent in HPV-positive cases than HPV-negative cases, consistent with the previous report that promoter methylation of RASSF1A is inversely correlated with HPV infection in head and neck and cervical cancer [11, 34].