As reported by Forbes, researchers continue to make progress in manipulating cell signaling to spur regeneration - a path that can be distinct from stem cell or gene therapy. This is a comparatively simple example of the type, and at an early stage in development, but still progress: "Normally, adult human hearts do not regenerate because the heart doesn't make more cardiomyocytes (heart muscle cells) after injury. It would be desirable to induce the heart to make new cardiomyocytes after injury. ... To that end, Kuhn's team created a patch that contains a compound called periostin, which helps cardiomyocytes divide and multiply ... Periostin is a natural component of tissue surrounding cells. It comes from the skin lying around bone and helps stimulate cells to divide. ... They placed the patches on the damaged heart muscle of rats in which they had induced a heart attack. After 12 weeks, the rats treated with the periostin patch experienced a 16 percent improvement in their heart's cardiac pumping ability. They also had less scarring of heart tissue, a reduction in the size of the damaged area of the heart, and more blood vessels feeding the area."