CXCR4 and pulmonary fibrosis: However, the degree of lung fibrosis was significantly alleviated in the G-CSF-pretreated CON-RNAi-BM-MSC (1 × 107/mL) group compared with the BLM group and the G-CSF-pretreated CXCR4-RNAi-BM-MSCs (P < 0.05; Figures 5(a)–5(e)), but there was no antifibrotic effect when the BLM-induced mice received a tail vein injection of the G-CSF-pretreated CXCR4-RNAi-BM-MSCs (Figures 5(a)-5(e)).