In addition, we detected the protein level of monocyte chemokine CCL-2 in BALF and lung tissue by ELISA, and the results also found that CCL-2 was significantly increased after CS exposure, while miR-23a-5p agomir could effectively inhibit the protein level of CCL-2 (Additional file 2: Fig. S2B, C), which might inhibit inflammatory cell recruitment. This evidence concerns the gene CCL2 and Cowden syndrome 1.