There had not been experimentation into muscle transplantation. In 1990 there were healthy muscle cells taken from another individual, then injected into a person with MD. They were optimistic that maybe these would cause good muscle cell growth. Researches used a hormone called insulin growth factor 1 (IGF-1) on rats with MD. This injected hormone showed the enhancement of voluntary muscle, new formation of good muscle cells, and generally stopped atrophy in the rats. Researchers are hopeful to maybe carry this over into studies with actual people. Also with mice there are studies going on to use the proteins Myostatin, and Utrophin. The intended use of Myostatin would be to prevent muscle deterioration, which in being studied in rats with MD. Utrophin is similar to Dystrophin and is trying to be put into drugs that would help decrease MD symptoms