Buloxibutid (AT2 receptor agonist C21) is an orally active, selective angiotensin II type 2 receptor (AT2R) agonist, with a Ki value of 0.4 nM for porcine AT2R. Buloxibutid exerts effects such as vasodilation, anti-inflammation, anti-fibrosis (promoting the expression of collagenase MMP-13) and tissue repair mainly by activating the NO/cGMP pathway, inhibiting the pro-proliferative MAPK signaling, and suppressing the pro-fibrotic TGF-beta/Smad pathway as well as the inflammatory NF-kappaB pathway. Buloxibutid can be used in research related to idiopathic pulmonary fibrosis, hypertension, and systemic sclerosis[1][2][3][4].