CD4 and systemic lupus erythematosus: It seems possible that SLE per se, as a low-grade inflammatory condition caused by constant antigenic stimulation, through an over-activation of the immune system, leads to proliferation and differentiation of naïve T cells into activated cell types altering the expression of certain CD4 receptors and leading to senescent subtypes that amplify autoimmunity via the production of pro-inflammatory cytokines during activation [19,33,34], although this effect is potentially reversible when disease goes into remission.