Based on emerging reports of potentially important roles for some of the newly discovered human β-defensins in lung defense (hBD3, hBD5, hBD8, hBD9, hBD18) [18,24,33], and the emerging role of hBD1 in COPD [11], we chose to study this selected set of the human β-defensin genes that had not been previously examined for their alteration following exposure to cigarette smoke (CSE) [29,35]. This evidence concerns the gene DEFB109B and chronic obstructive pulmonary disease.