MTHFR and urinary bladder carcinoma: While systematic reviews predominantly find their foothold in clinical setting comparisons and evaluations of natural compound studies [25,26,27,28,29,30], our research undertook a meticulously orchestrated systematic review, aimed at penetrating the intricate realm of the association between the methylenetetrahydrofolate reductase rs1801133 polymorphism and the incidence of bladder cancer (BC).