HDAC2 expression in the airway epithelium (as measured by percentage area of epithelium stained for HDAC2) was not significantly different between the groups (Figure 2 and 3), [median (range); NC 25.3% (1.1%–29.3%); NS 24.9% (10.2%–29.6%); COPD-CS 20.8% (8.6%–31.2%); COPD-ES 24.7% (0%–30.6%) p = 0.7], although it was reduced on average in the current smoking COPD but with wide inter-subject scatter. The gene discussed is HDAC2; the disease is chronic obstructive pulmonary disease.