This video discusses the enzyme and transporter expression levels that are defined in various tissues, e.g., GI tract, liver, lung, kidney and species (human, dog, monkey, and rat). Several enzymes and transporters for pre-clinical species were added for GastroPlus 9.6. First pass metabolism of verbenone is demonstrated by inputting Km and Vmax for CYP2c11 in a PBPK model. This makes use of the newly added CYP2c11 expression level in rat liver tissue to yield oral bioavailability.