Ziora et al. on the other hand did not demonstrate any correlation between FENO and other markers of inflammation in induced sputum such as nitrogen oxides (nitrite or nitrate) and cytokines (IL-8, TNF-α, TGF-β1, GM-CSF, eotaxin) except for a negative correlation with the cytokine GM-CSF (r = −0.38, P = 0.02) in patients with all stages of COPD.[78]. The gene discussed is CXCL8; the disease is chronic obstructive pulmonary disease.