These data are in accordance with what already published (De Falco et al., 2017a) in that healthy and smokers have higher levels of OGG1, a repairing DNA enzyme, compared to COPD-derived PBMCs, who have reduced levels of the enzyme to counter the oxidative stress damage to DNA due to higher levels of ROS. Here, OGG1 is linked to chronic obstructive pulmonary disease.