Greater understanding of the mechanisms of healing brings more opportunities to enhance the body's natural powers of regeneration. Here, researchers "provide conclusive proof that, when a muscle is injured, white blood cells called macrophages play a crucial role in its regeneration. The scientists also uncovered the genetic switch that controls this process, a finding that opens the door for new therapeutic approaches not only to sports injuries but also to diseases such as Duchenne muscular dystrophy. ... After clearing [an injured region], macrophages stop [releasing] pro-inflammatory factors, and start making anti-inflammatory factors that promote repair in the damaged area. This shift from clearing debris to promoting building is known as macrophage polarization ... Normally, inflammatory factors trigger an increase in C/EBP-beta production, which in turn activates genes that cause the macrophage to polarize. ... From a medical point of view, it would seem that the trick to improve muscle repair is finding a way to increase C/EBP-beta production and keep it high. If we can now figure out exactly which key genes C/EBP-beta controls, that will give us even more potential targets [to enhance healing].