For instance, IL2 promotes the development of CD4+CD25+FoxP3+ Tregs (Malek et al., 2000; Malek, 2003; Burchill et al., 2007), that represent an immunomodulatory T cell specialized subset able to neutralize the development of immune-mediated damage and to promote repair and regeneration of affected target-organs in systemic immune diseases (Sakaguchi et al., 1995; Gatza et al., 2008). This evidence concerns the gene CD4 and immune system disorder.