CCR1 and idiopathic pulmonary arterial hypertension: Animal models and human studies have revealed that inflammatory mediators are upregulated, including chemokines and chemokine receptors in IPAH (10, 11), such as CXCL10/CXCR3, CXCL8/CXCR1/CXCR2, CCL2/CCR2, CXCL12/CXCR4/ACKR3, CX3CL1 /CX3CR1, CCL5/CCR5/CCR1 (10, 33).