Th17 (CXCR3+) cells ranged from 0.9% to 1.3% [0.2–5.2], Th17 (CXCR3-CCR4+) cells from 0.3% to 0.7% [0.0–1.3], and Th17 (CXCR3-CCR4-) cells from 26.1% to 31.7% [10.5–81.6].” Similar to COPD and IPF, IPAH patients demonstrated increased lung tissue Th1 lymphocytes (Table 2). Here, CXCR3 is linked to idiopathic pulmonary fibrosis.