CYP2D6*35 is assigned normal function based on moderate evidence in heterozygous subjects. CYP2D6*35 was first identified in a subject with CYP2D6*5/*35 genotype demonstrating similar dextromethorphan metabolism compared to CYP2D6 *1/*5 subjects, indicating normal function of the CYP2D6*35 allele (9241659). Similarly, a subject with CYP2D6*4/*35 genotype demonstrated decreased dextromethorphan metabolism compared to wildtype subjects (21833166). Additionally, a study of 396 subjects found the -1584C>G substitution, which is found in CYP2D6*35 and other normal function alleles such as CYP2D6*2, was not observed in any subject demonstrating poor dextromethorphan metabolism, indicating normal function of the CYP2D6*35 allele (12766015). Although two in vitro studies found CYP2D6*35 had decreased enzyme activity compared to wildtype (24647041, 30366777), experts did not find these results convincing as the expression system may not be reflective of in vivo environment as demonstrated by the numerous subjects carrying the CYP2D6*35 allele with substrate metabolism similar to that of wildtype as described previously. Therefore, consensus among experts was normal function with an activity value of 1 based on moderate evidence.