MTHFD2 is an enzyme involved in one-carbon metabolism within the mitochondria and is upregulated in various types of solid tumors [36,38], such as lung adenocarcinoma [36], hepatocellular carcinoma [39], renal cell carcinoma [40], colorectal cancer [41], and breast cancer [42]. The gene discussed is MTHFD2; the disease is renal cell carcinoma.