The aims of this monograph were to investigate the genetic polymorphisms of tumor necrosis factor alpha and transforming growth factor-beta 1 in different disorders. We focused on such gastrointestinal, autoimmune, hematological diseases, where the overproduction of these cytokines might be a predominant factor in the pathomechamisms, or where anti-TNF therapy has been introduced. In a close connection the single nucleotid polymorphisms of CD14 and heat shock protein 70-2 genes were also analyzed. The present study was designed to determine the correlation of TNF-alpha, HSP70-2, and CD14 gene polymorphisms and the severity of acute pancreatitis. The prevalence of TNF-alpha and HSP70-2 gene polymorphisms in a family with rheumatoid arthritis was also investigated. The prognostic value of TNF-alpha gene polymorphism among patients treated with anti-TNF-alpha therapy, and the effect of anti-TNF-alpha therapy on TNF-alpha production and apoptosis was also determined. Finally, the association between TNF-alpha and TGF-ß1 gene polymorphism and the susceptibility to myelodysplastic syndrome was investigated.