CCR2 and pulmonary arterial hypertension: Indeed, Abid and colleagues (2018), using animal models of PH and PH human samples, demonstrated the importance of the crosstalk between PASMCs and macrophages via the chemokine receptors CCR2 (chemokine receptor 2) and CCR5 (chemokine receptor 5), as an essential mechanism affecting both cell types, and determining the migration and proliferation of PASMCs during the development and progression of PAH [142].