The authors report preliminary data about IF-gamma (Interferon-gamma) basal serum production tested by monoclonal antibody in three groups of 25 patients: alpha (normal controls), beta (ragweed hayfever patients) and gamma (laryngeal carcinoma patients pT3-4, pN0----3, pM0 by UICC). The IF-gamma mean value in ragweed hayfever patients is about five times higher then normal controls. These data are highly statistically significative. Moreover no value of IF-gamma basal serum production is tested in laryngeal carcinoma patients. The data are discussed.