CCL2 and acute respiratory distress syndrome: The main findings of our present study can be generalized as follows: (1) ALI exaggerates pulmonary inflammation and injury accompanied by the downregulated p‐YAP1 and upregulated activity in the lung; (2) inhibition of YAP1 activity attenuates the development of lung injury and improves pulmonary function in ALI mice; (3) inhibition of YAP1 activity suppresses M1 polarization while induces M2 polarization in ALI mice; (4) YAP1 deficiency decreases CCL2 levels and promotes macrophage polarization towards M2 phenotype in BMMs.