Bisulfite pyrosequencing of the promoter region of human AMP beta-defensin-1 (HBD-1) showed significantly higher methylation frequencies at the CpG 3 and CPG 4 sites in AD lesional samples than in non-lesional AD skin and healthy skin samples [103], suggesting that promoter DNA methylation contributes to HBD-1 deficiency in AD. The gene discussed is DEFB1; the disease is Alzheimer disease.