CD4 and chronic kidney disease: In conclusion, our present study demonstrated for the first time that low-dose IL-2 can expand CD4+CD25+FoxP3+Tregs preferentially via the STAT5 pathway in PBMCs from CKD patients with chronic glomerular diseases in vitro, and the expanded Tregs exert potential suppressive function on the production of proinflammatory Th1 and Th17 cytokines.