CD4 and systemic sclerosis: In systemic sclerosis (SSc), a rare connective tissue disease characterized by chronic inflammation and fibrosis with deleterious effect in the kidney, DNA hypomethylation in CD4+ T-lymphocytes from SSc patients decreased the expression of methylation genes such as DNA methyltransferases (DNMT)1 and methyl-CpG-binding domain proteins (MBD)3 and MBD4 [46, 47].