So far, we have noticed that cancer cells depend on the methionine cycle more, so if we can target both the transsulfuration pathway (via CBS) and the remethylation pathway at the same time, as shown in Figure 5, then these cells will build up toxic Hcy and inhibit the production of H2S. High levels of Hcy will induce apoptosis, protein oxidation, and oxidative and ER stress and inhibit angiogenesis, whereas low levels of H2S will inhibit cancer growths; as a result, tumor progression will be inhibited due to the effects of high Hcy and low levels of antioxidants like H2S. This evidence concerns the gene CBS and cancer.