Inclusion of Additional Significant Influencing Factors. Additional significant influencing factors were included in adults' FeNO norms [9–24]: race, ethnicity, atopy, allergy, total IgE, serum eosinophil cationic protein, smoking status, interaction between sex and smoking habits, asthma diagnosis, ambient NO, and upper respiratory tract infection symptoms. The gene discussed is RNASE3; the disease is asthma.