HDAC2 and chronic obstructive pulmonary disease: Thus, NS were significantly different from all other groups [median (range); NS, 82.1% (49.1%–93.5%) versus NC, 68.2% (27.6%–80.1%), COPD-CS, 54.3% (17.8%–69%), COPD-ES, 66.8% (1.20%–84.3%) p<0.001], with smoking apparently stimulating HDAC2 expression.