ADORA2A and pulmonary fibrosis: To investigate baicalin’s anti-fibrosis effect, a study in mice with knocked-out adenosine A2a receptor (A2aR), which is an inflammatory regulatory receptor, found that, compared with A2aR-positive mice, A2aR-knockout mice had more severe pulmonary fibrosis and higher expression levels of TGF-β1 and phosphorylated ERK1/2 protein [96].