Although reduced HDAC2 is associated with corticosteroid insensitivity in smokers and patients with severe asthma, chronic obstructive pulmonary disease, nephrotic syndrome and Sudden Sensorineural Hearing Loss insensitive to corticosteroid treatment (16, 39, 40), we did not find a differential HDAC2 expression in corticosteroid-sensitive and corticosteroid-insensitive ILDs. Here, HDAC2 is linked to chronic obstructive pulmonary disease.