MTHFR and urinary bladder carcinoma: Meta-analyses, other reviews, and original papers have been describing associations of this MTHFR variant with several types of cancers, such as ovarian cancer, breast cancer, colorectal cancer, bladder cancer, lung cancer, childhood acute lymphoblastic leukemia [71,72,73,74,75,76], and even cervical cancer [77,78,79,80,81].