Of the five initial genes selected for evaluation (DAPK, RASSF1A, PAX5β, CDH1, p16) based on their literature reported, methylation-specific PCR (MSP)-based prevalence in lung tumors (>25%), diversity of function, and timing for inactivation during lung cancer development, where known, we chose to pursue the three that showed any promoter methylation at all. Here, RASSF1 is linked to lung cancer.