However, Do exhibited the lowest importance among the three key GUTFW parameters, contrary to our initial prediction. This may be due to the lack of accurate dosage information when Fa was observed. This is because the dosage we collected was not always the same as that used in human clinical studies to investigate Fa. In a few cases, we made a few assumptions; for example, the p.o. dose is the same as the i.v. dose, or the dose of the pro-drug is the same as the dose of the active form (see Table for details).