CD4 and chronic obstructive pulmonary disease: Additionally, Xia Yang and colleagues [35] discovered that individuals with stable COPD had notably higher proportions of CD4+CD25+CD45RO+ Tregs, but lower counts of CD4+CD25+CD127low Tregs, CD4+CD25+CD45RA+ Tregs, and CD4+CD25+CD62L+ Tregs, suggesting a shift towards immune tolerance in patients with COPD due to an imbalance between immunosuppressive and immunoenhancing CD4+CD25+ T cell subsets.