RB1 and cervical cancer: The methylation status of both genes increased with disease progression, showing the lowest frequencies in the control (6.7% for RB1 and 13.3% for CDH1) and LSIL samples (5.8% for RB1 and 11.8% for CDH1) and the highest in cervical cancer samples (50.0% for RB1 and 33.3% for CDH1).