DAPK1 and lung cancer: 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.