CYP2C9*7 is assigned uncertain function based on inadequate evidence due to conflicting in vitro data and no clinical data. In an in vitro study CYP2C9*7 demonstrated 47% warfarin clearance compared to wildtype, however, similar tolbutamide clearance compared to wildtype was demonstrated in the same study as well as a separate study (23752738, 15284535). Therefore, consensus among experts was not achieved and uncertain function was assigned.