Figure 1: Skeletal muscle regeneration and muscle resident stem cells. The figure depicts a cross-section of skeletal muscle showing myofibers surrounding a blood vessel and the localization of several types of muscle-resident stem cells. The satellite cells (SCs) are located at the periphery of the myofibers, beneath the basal lamina, and become activated upon damage. The activated SCs start expressing myogenic factors, including MyoD and progress to become myoblasts. Myoblasts upregulate the expression of the differentiation factor myogenin (Mgn) and differentiate into myocytes that finally fuse together (forming neofibers) or to damaged myofibers. The figure is adapted from Kuang et al. [114] Trends Mol Med 14: 82-91.