Secondly, highly expressed MTHFD2 is associated with poor disease outcomes in breast cancer (2), colorectal cancer (CRC) (3), renal cell carcinoma (RCC) (4), and hepatocellular carcinoma (HCC) (5); upregulation of MTHFD2 may also contribute to an increased risk of bladder cancer (6). This evidence concerns the gene MTHFD2 and breast cancer.