2. Substrates for p-glycoprotein transporter (e.g., ambrisentan, digoxin), OCT1 transporter (e.g., metformin), OAT1 transporter (e.g., captopril, furosemide, methotrexate), and OATP1B3 transporter (e.g., atorvastatin, rosuvastatin, valsartan);