CXCL12 and pulmonary arterial hypertension: Promisingly, further investigations showed that neutralizing the activity of the chemokine CXCL12 (also known as SDF1) using the naturally occurring neutraligand chalcone 4 was able to suppress early pericyte accumulation at the pulmonary arterioles of mice, suggesting that the CXCL12 pathway may be a viable target for the treatment of PAH.