Muscle is a stage, and cells and factors are merely players

The incredible ability of satellite cells to regenerate muscle has captivated much of the research field's attention over the past decades. Versatile, enigmatic, vigorous, and skillful, the satellite cell is the optimal actor to cast in a regenerative epic, grabbing contracts and making headlines. However, the scenarios that play out during normal muscle usage, such as during exercise and aging, diverge from the experimental setup staged to spotlight satellite cells. Recent studies examining myofibers have highlighted novel attributes, including a capacity for self-repair. We discuss here the distinctions between myofiber self-repair and satellite-cell-dependent regeneration and how they may cooperate to repair damage after exercise, in myopathies, and in aging.