Figure 5From: Multidrug resistance-associated protein-1 (MRP1) genetic variants, MRP1 protein levels and severity of COPD Summary of MRP1 SNPs' associations for COPD patients. FEV1 = forced expiratory volume in one second; MRP1 = multidrug resistance-associated protein-1; ↑ = positive association; ↓ = negative association; - = no association.Back to article page