IGHE and allergic disease: Research activity of Professor Rasi in the area of allergy and clinical immunology includes studies (performed in collaboration with Sergio Bonini, Tom Platts Mills, Bruce Mitchell, and Martin Chapman) on the influence of environmental factors (infectious agents, smoking) on IgE production and on the genetic effect in atopic twins on the serum levels of IgE and IgG4 antibodies to major molecular allergens).