In 2006, Suarez et al. reported that systemic lupus erythematosus (SLE) patients had a higher percentage of CD4+CD25high Treg cells than healthy subjects; however, a sub-analysis of the data demonstrated that the higher percentage of Treg cells (about two-fold) was present only in the patients treated with GCs [136]. This evidence concerns the gene CD4 and systemic lupus erythematosus.