CYP2C9*33 is assigned no function based on limited evidence. Multiple in vitro studies using different cell systems found CYP2C9*33 demonstrated decreased clearance for numerous substrates compared to wildtype and similar clearance compared to CYP2C9*3 which definitively has no function (23752738, 18971529, 23844998, 24118918, 25142737, 25951663, 25144335, 25476996, 25832633, 25884291, 27163851, 19541829, 24077631). Although one patient with CYP2C9 *1/*33 genotype had their blood pressure lowered with losartan, the experts did not find this result convincing due to the small sample size (18971529). Therefore, consensus among experts was no function with an activity value of 0 based on limited evidence as it was determined the phenotypes containing this allele would be clinically distinct from phenotypes comprising normal and decreased function alleles.