Homocysteine has metabolic cofactors, including vitamin B12, folate, and vitamin B6. Homocysteine is also affected by various other factors including mutation in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene, renal failure, malignancy, immunological diseases, drugs, and lifestyle [31]. The gene discussed is MTHFR; the disease is acute kidney injury.