In human patients, increased levels of MBD2 and global demethylation in CD4+ T cells has been observed in several autoimmune disorders, including systemic lupus erythematosus (Balada et al., 2007; Liu et al., 2011), systemic sclerosis, dermatomyositis (Lei et al., 2009) and MBD2 was determined to be a susceptibility locus for psoriasis (Tsoi et al., 2012). Here, MBD2 is linked to systemic lupus erythematosus.