Groups 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Mean Involved epidermis 0.027 0 0.037 0.007 0.013 0.033 0.049 0.065 0 0 0 0 0 0.052 0.015 0 0 0.02 0 0 0.047 0.047 0.035 0.042 0.073 0.034 0.023 Uninvolved epidermis 0 0 0.063 0.013 0.015 0.045 0.063 0.028 0.017 0 0.04 0.011 0.03 0.015 0 0 0 0 0 0.033 0.015 0 0.033 0.013 0.027 0.027 0.0188 Controls 0 0 0.018 0 0 0.012 0 0 0 0 0 0 0 0 0 0 0 0 0 0.018 0 0 0.041 0.047 0.08 0.052 0.0105

Table 2: Methylation rates of 26 CpG sites in a 405 bp region of IL-12B gene (-1166~ -762) in involved psoriatic epidermis, uninvolved psoriatic epidermis and healthy controls.