CCR4 and chronic obstructive pulmonary disease: Both COPD and IPF patients exhibited approximately 2.9-fold higher percentage of CD4+ lung tissue Th1 CXCR3+CCR4-CCR6- cells in comparison to Th1 tissue cells in healthy donor lungs (Table 2, Figure 3A) (p ≤ 0.0048; 33.2% [12.4–48.3], 31.9% [24.0–50.5] vs. 11.6% [7.48–27.0]), respectively).