Vladimir Lenin led the Bolshevik Revolution, helped create the Soviet Union and launched the communist era in Russia. Learn more at Biography.com. Vladimir Lenin was founder of the Russian Communist Party, leader of the Bolshevik Revolution and architect and first head of the Soviet state.
The disadvantages come entirely from the source of stem cells. For embryonic stem cells, a human blastula (the collection of cells that will eventually become a fetus) must be sacrificed. This brings forth an image of sacrificing babies for science, and needless to say, many folks have a problem with that.
Although research into adult stem cells is promising, adult stem cells may not be as versatile and durable as are embryonic stem cells. Adult stem cells may not be able to be manipulated to produce all cell types, which limits how adult stem cells can be used to treat diseases.