CD4 and systemic sclerosis: To investigate the level of DNA methylation of CD11a regulatory elements in SSc CD4+ T cells, the methylation status of 23 CG pairs in 1,699 bp of the CD11a gene promoter (-1486 to +213) containing the Alu elements, transcription factor binding sites and transcription start site was analyzed using bisulfite genomic DNA sequencing (Figure 2).