MTR and neoplasm: The dependence of tumours on methionine synthase for various cell lines in comparison to the normal cells has been previously reported [77–79]. L-Methionine is required for the synthesis of vitamins, antioxidants, DNA stabilizers, epigenetic DNA modulators, coenzymes [61, 80, 81], proteins, polyamines (proper cell development), antioxidative stress defense (glutathione/trypanothione), iron-sulfur cluster biosynthesis (energy metabolism), and methylation reactions and it also regulates the gene expression [5–8, 78].