DAPK1 and head and neck squamous cell carcinoma: With the control source, the significant association between DAPK promoter methylation and HNSCC was found among the autologous group and the heterogeneous group in the random-effect model (autologous group, OR = 2.71, 95% CI = 1.49–4.93; heterogeneous group, OR = 9.50, 95% CI = 2.98–30.27).The results suggested that the frequency of DAPK promoter methylationin the autologous control was higher than the heterogeneous control.