Because positive thyroid antibodies (similarly to other kind of antibodies) result from the weakening of the immune system and because the association was found between MBL gene polymorphisms and susceptibility to autoimmune thyroid diseases (40) we checked whether the prevalence of positive thyroid antibodies differs between particular groups and whether mean MBL levels differ in individuals with positive versus negative thyroid antibodies. The gene discussed is MBL2; the disease is autoimmune thyroid disease.