 Baseline CYP profile: Subjects will return to the GCRC at a specified time in the morning prior to probe drug administration. In the morning, an indwelling venous catheter will be placed in each subjects arm to facilitate serial blood sampling. At 8AM, after urinary void, subjects will be asked to take simultaneous single oral doses of 2 mg ALPZ, 100 mg CAF, 100 mg TOL, and 30 mg DM. At this time, a urine collection will commence for the first eight hours of the visit. A total of 11 blood samples 10 ml each will be taken over a 12-hour period. Time points of blood collection will be immediately before drug administration, and at 0.5 hours, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, 8.0, and 12 hours. Additionally, the subjects will be asked to return for 4 more brief visits for collection of single blood samples through a separate venipuncture at time points of 24, 36, and 48 hours. This extended sampling will provide adequate pharmacokinetic data to determine Cmax, AUC, terminal t12, and Clo of all probe drugs. To reduce any potential variability in drug absorption due to food, the subjects will be in a fasted state for 4 hours following probe drug administration. Standard meals will be served by the registered dietician at the GCRC and will not include grapefruit, artichoke products, or CAF. The composition and amount of food eaten throughout the day will be recorded. 