CD4 and systemic sclerosis: Finally, Mathian et al. analyzed circulating activated (a)Tregs (CD4+CD45RA(CD25bright T cells) and resting (r)Tregs (CD4+CD45RA+CD25+ T cells) in controls and SSc and found decreased frequency but normal suppressive function of both types of Tregs and in the lesional skin found no CD4+Foxp3 mRNA in SSc compared to normal donor skin (211).