MTR and breast cancer: On the other hand, the study by Ma et al. (2009), where the role of the SNPs MTHFR rs1081133 (G > A) and rs1081131, and MTR rs1805087, as well as the dietary intake of folate, B6 and B12 was explored among 458 women with breast cancer and 458 women without the disease from Brazil (mixed origin), showed that the GG genotype of the MTR rs1805087 increases the risk of overall breast cancer (OR = 1.99, 95%CI = 1.01–3.92; p = 0.01), while no association was observed for the MTHFR SNP rs1081133.