however, depending on the severity and frequency of the injury, the regeneration process of skeletal muscle is very slow and incomplete, resulting in strength loss, fibrosis and a high rate of re-injury at the site of the prior injury. fibrosis is triggered mainly by the expression of transforming growth which stimulates fibroblast proliferation and collagen synthesis; and, concomitantly, inhibits both satellite cell proliferation and differentiation into myotubes.