However, the results of the study by Sicinska et al. were different, as they analyzed blood samples from 30 patients with COPD and 18 healthy subjects in a controlled manner and found that BCHE activity was significantly reduced in the blood of patients with COPD, which was accompanied by an increase in lipid peroxidation and a decrease in total antioxidant capacity (31). This evidence concerns the gene BCHE and chronic obstructive pulmonary disease.