Other SNPS in genes involved in the folate metabolism are: rs1801131 [259–262] and rs1801133 [260–265] in MTHFR that are widely classified as risk factors for BC, whereas rs1476413 in the same gene decreases the risk of cancer occurrence [266], rs1805087 in MTR increases the risk for BC in the Tunisian population [262, 267] and rs1801394 in MTRR increases the risk for BC only in Saudi Arabia [18]. Here, MTHFR is linked to cancer.