{{Rsnum
|rsid=3740065
|Gene=ABCC2
|Chromosome=10
|position=101605693
|Orientation=minus
|GMAF=0.185
|Assembly=GRCh37
|GenomeBuild=37.1
|dbSNPBuild=131
|Summary=Patients receiving tamoxifen have shorter recurrence-free survival
|geno1=(C;C)
|geno2=(C;T)
|geno3=(T;T)
}}
{{ population diversity
| geno1=(C;C)
| geno2=(C;T)
| geno3=(T;T)
| CEU | 2.7 | 14.2 | 83.2
| HCB | 13.9 | 44.5 | 41.6
| JPT | 8.0 | 51.8 | 40.2
| YRI | 3.4 | 32.7 | 63.9
| ASW | 3.5 | 29.8 | 66.7
| CHB | 13.9 | 44.5 | 41.6
| CHD | 12.8 | 41.3 | 45.9
| GIH | 0.0 | 39.6 | 60.4
| LWK | 8.2 | 36.4 | 55.5
| MEX | 0.0 | 20.7 | 79.3
| MKK | 7.1 | 35.9 | 57.1
| TSI | 0.0 | 34.3 | 65.7
| HapMapRevision=28
}}

[[rs3740065]] is a SNP in the ATP-binding cassette, sub-family C (CFTR/MRP), member 2 [[ABCC2]] gene.

A study of 282 hormone receptor-positive, invasive [[breast cancer]] Japanese patients receiving [[tamoxifen]] found a significant association with shorter recurrence-free survival (p = .00017; hazard ratio 10.64, CI: 1.44 - 78.88) in [[rs3740065]](T;T) patients; the hazard ratio for carriers of one (T) allele was 3.5 (CI: 0.5-26).{{PMID|20124171}} Curiously, no significant difference in plasma levels of the tamoxifen metabolites endoxifen or 4-hydroxytamoxifen were seen.

This same study of [[tamoxifen]] users concluded that [[rs3740065]](T;T) patients who also had two CYP2D6 risk alleles had a 45 fold higher risk of recurrence than patients with zero or one (out of the possible four) risk alleles. The overall average recurrence risk was 5x for carriers of a total of two risk alleles, and 20x for carriers of a total of three risk alleles.{{PMID|20124171}}

A nearby SNP, [[rs11190303]], also showed significant association to recurrence-free survival; it was shown to be strongly linked to [[rs3740065]] (r2 with LD of 0.79).{{PMID|20124171}}

{{PMID Auto
|PMID=23222202
|Title=Polymorphisms in the methotrexate transport pathway: a new tool for MTX plasma level prediction in pediatric acute lymphoblastic leukemia.
}}

{{on chip | 23andMe v1}}
{{on chip | 23andMe v2}}
{{on chip | 23andMe v3}}
{{on chip | 23andMe v4}}
{{on chip | Affy GenomeWide 6}}
{{on chip | FTDNA2}}
{{on chip | HumanOmni1Quad}}
{{on chip | Illumina Human 1M}}