IL4 and periodontitis: The aim of this study was to assess the influence of IL-4 (-590C/T) and IL-4 VNTR (variable number of tandem repetitions in intron 3 gene) polymorphisms on cytokine production after stimulation of isolated peripheral blood mononuclear cells by dental plaque bacteria, mitogens, and HSP70 in patients with periodontitis and in healthy controls.