HGF and chronic obstructive pulmonary disease: Mazzone et al. [22] (Mazzone, Wang et al. 2018) also validated a panel of biomarkers, including hepatocyte growth factor (HGF), CEA, CYFRA21-1, CA125, and New York esophageal cancer-1 antibody (NY-ESO-1), together with clinical variables (including age, sex, COPD status, and smoking history).