This was proven in in vivo and in vitro studies which concluded that genistein was responsible for the inhibition activity of DNA methyltransferase (DNMT) [18], downregulation of DNA methylation, and DNA (cytosine-5)-methyltransferase 1 by its ability to demethylate and reactivate methylation-silenced tumor repressor genes [46]. The gene discussed is DNMT1; the disease is neoplasm.