In vivo, MCETs were identified in psoriatic lesions and in skin explant cultures treated with IL‐23 and/or IL‐1β by using immunofluorescence with tryptase and DAPI 17, while EETs were detected in the intestines of patients with Crohn's disease 20, in skin diseases 19, and in bronchial biopsies of asthmatic patients 40 with the use of DNA and EMBP immunostaining. The gene discussed is PRG2; the disease is Crohn disease.