The variations of S100A12 gene expression and the promoter methylation assay. (a) We used qPCR to examine the relative mRNA levels of S100A12 in total WBCs as suggested by a previous study22. The variation tendency of the S100A12 gene in the WBCs was consistent with that of the S100A12 protein in serum. Data was presented as 2-ΔΔCt with 18S gene as internal control. (b) Compared with empty pGL3 vector, pGL3-S100A12 demonstrated promoter activity. (c) The construct carrying the S100A12 promoter and luciferase was treated with M.SssI (totally methylated) or untreated (non-methylated), followed by transfection and luciferase assays. Data were presented as the mean ± SD. ** and *** denoted p-values < 0.01 and 0.001 according to t-tests, respectively.