CD70 and pulmonary fibrosis: In this study specific genes that were found to be hypomethylated include CTGF, CXCR4, CD70, MT-1G, THY1, CDKN2A, SOCS1, FLI1 and DNMT1. CTGF is known to be constitutively upregulated in SSc and has been hypothesized to be a key mediator of pulmonary fibrosis due to its overexpression which correlates well with severity of lung fibrosis frequently observed in this disease [12].