Smoking status is presented as absolute numbers (percentages), and all other data are presented as the median (interquartile range), except for age that is presented as median (minimum – maximum); data were analysed by Mann-Whitney Rank Sum test.COPD – chronic obstructive pulmonary disease. FEV1 - forced expiratory volume in 1 second. FVC - forced vital capacity. CRP - C-reactive protein. Fbg – fibrinogen. WBC - white blood cells. Plt - platelet count. PLR - platelet to lymphocyte ratio. MPV - mean platelet volume. PDW - platelet distribution width. Pct - plateletcrit. The gene discussed is CRP; the disease is chronic obstructive pulmonary disease.