IGHE and airway hyperresponsiveness: There was a positive correlation between SOCS1 staining scores and numbers of positive skin prick test responses, with a similar nonsignificant trend for IgE levels (data not shown) and a negative correlation with the provocative concentration of histamine causing a 20% reduction in lung function (PC20 histamine), indicating greater intensity of SOCS1 staining was related to greater severity of atopy and airway hyperresponsiveness (Fig 2, B).