ACE: angiotensin-converting enzyme; NSAIDs: non-steroidal anti-inflammatory drugs; HIV/AIDS: human immunodeficiency virus/acquired immunodeficiency syndrome; HCV: hepatitis C virus; HBV: hepatitis B virus; HSV: herpes simplex virus; PTEN: phosphatase and tensin homolog; BRCA 1 & 2: breast cancer 1 & 2; HNPCC: hereditary non-polyposis colorectal cancer; CT: computed tomography; WTC: World Trade Center; COPD: chronic obstructive pulmonary disease. This evidence concerns the gene PTEN and chronic obstructive pulmonary disease.