By screening titles and abstracts, 148 studies were excluded because they were 1) meta-analyses or reviews (n = 29), 2) letters, editorials, abstracts, and case reports (n = 10), 3) studies on animals or cell lines (n = 61), 4) studies not on TNF-α (n = 34), studies not for case-control study(n = 1), and 5) studies not on OSA (n = 13). The gene discussed is TNF; the disease is obstructive sleep apnea syndrome.