As steroid suppresses the activation of pro-inflammatory genes by recruiting histone deacetylase 2 (HDAC2) (Ito et al., 2000), a reduction in HDAC2 expression and activity had been linked with increased inflammation in chronic obstructive pulmonary disease (COPD) and bronchial asthma patients (Ito et al., 2002, 2005, 2006). Here, HDAC2 is linked to chronic obstructive pulmonary disease.