TNF and atherosclerosis: The most common gene polymorphism in human PPARγ2 gene is cytosine-guanine exchange in exon B (codon12) which results proline to alanine (Pro12Ala) substitution in the protein [6].The Pro12Ala polymorphism was first identified by Yen et al.[7] in 1997 and regarded to reduce transcriptional activity of PPARγ2 [8], resulting in lower transcription levels of target genes [9],including tumor necrosis factor α (TNF α), leptin, resistin, adiponectin, and plasminogen activator in hibitor-1(PAI-1), which play important roles in the process of inflammation and atherosclerosis.