Although the top loci associated with lung function were not associated with vitamin C treatment, we identified a highly significant lung function DMR near POU5F1 and PSORS1CS. PSORS1CS promoter activity is responsive to the glucocorticoid dexamethasone and in turn modulates POU5F1/OCT4 expression, which is proposed to explain association of this psoriasis susceptibility candidate with various immune related diseases [62] and may also explain the observed association with lung function. The gene discussed is POU5F1; the disease is psoriasis.