To validate and replicate the differentially methylated CpG sites identified with the 450k microarray data, bisulfite pyrosequencing was carried out for four hypomethylated genes, MX1, IFI44L, NLRC5 and PLSCR1, in a larger cohort of 100 controls and 100 SLE patients. The gene discussed is IFI44L; the disease is systemic lupus erythematosus.