In BALF taken from COPD patients, statistical analysis revealed a significant negative relationship between NK percentage and the number of pack years (r = −0.8033; p < 0.01), and a positive association between the number of pack years and CD27−/CD11b+ cells (r = 0.7699; p < 0.02). The gene discussed is ITGAM; the disease is chronic obstructive pulmonary disease.