TNF-α enhanced the expression of HLA class I and adhesion molecules on thyrocytes, and increased expression of the molecules on thyrocytes would promote the autoimmune responses related to the pathogenesis of TAO, besides the polymorphic allele of TNF-α gene at position 308 (G to A, -308A) or 238 (G to A, -238A) was found to be involved in severity of and susceptibility to some autoimmune and infectious diseases [32]. The gene discussed is TNF; the disease is infectious disease.