Because the reduction ofHDAC2 in patients with asthma could be due to inactivation of the enzyme by oxidativeand nitrative stress (10,35), we speculate that 1,25(OH)2D3 mightinhibit iNOS expression and activity, which would explain the increased HDAC2 expressionlevels in the 1,25(OH)2D3 pretreated and treated groups. The gene discussed is NOS2; the disease is asthma.