The results of two new studies indicate that it may one day be possible to repair damaged organs within the body, avoiding the need to transplant donor organs or use artificial devices. In one study, researchers were able to take mouse heart fibroblasts(繊維芽細胞), cells that give rise to connective tissue, and turn them into beating cells by inserting several genes into them. In the second study, mouse heart muscle cells began to grow and divide after researchers inactivated two specific genes that work to suppress tumor growth.