A nonsynonomous polymorphism, rs1242149 (c935G > A), in SLCO2B1 has been found to associate with significantly reduced plasma concentrations of montelukast and Asthma Symptom Utility Index (ASUI) in patients with asthma treated with montelukast for 6 months [119, 122]. Here, SLCO2B1 is linked to asthma.