It has been demonstrated that by reducing chemokine C-X-C motif ligand 12 (CXCL12) and C-X-C motif receptor 4 (CXCR4) signaling (135), as well as suppressing CXCL10 (131) and CCL2 (136), lung Tregs can play roles in controlling the recruitment of fibroblasts, thereby alleviating pulmonary fibrosis (135). Here, CXCL12 is linked to pulmonary fibrosis.