Unexpectedly, there was no difference in methylation levels between the promoter regions of SOCS-1 and SOCS-3; both were demethylated in A549 and L132 cells, which means that the activity of the SOCS family might not be regulated by promoter methylation in the A549 lung cancer cell line (Supplementary Figure S2). This evidence concerns the gene CISH and lung carcinoma.