Note: The pyrosequencing technique can only analyse fragments of DNA of up to 50 base pairs in one reaction. According to data from CpG Island Searcher, and when the % GC was set at 55%, observed CpG/expected CpG set at 0.65 and gaps between adjacent islands set at 100bp, no CpG islands can by found in either the IL-6, or the TNFα promoter. Therefore, the methylation status of the whole promoter region in both genes will be studied using 40 pairs of primers for each gene (in order to cover 2kb of the promoter region). This approach is adopted as it is the most sensitive and reliable for determination of site specific DNA methylation in an extended region such as a promoter region.