{{23andMe SNP 
| iid = 4001479
| Gene = CYP2D6 
| position = 40854764
| Chromosome = 22 
| geno1 = (-;-) 
| geno2 = (-;CC) 
| geno3 = (CC;CC)  
}}1973_1974insG insertion is a marker for the CYP2D6*20 non-functioning variant.

{{on chip | 23andMe v2}}
{{on chip | 23andMe v3}}
{{on chip | 23andMe v4}}