miRNA-221-5p may play critical roles in driving the differentiation of Th17/Treg ratio via RORγt/Foxp3 by Targeting SOCS1, reduced the function of Th17 cells by directly inhibiting RORγt/SOCS1 and promoted the function of Treg cells via Foxp3/ SOCS1 in asthma. This evidence concerns the gene FOXP3 and asthma.