Myogenin and MRF4 are secondary MRFs that are primarily involved in the later stages of muscle cell differentiation. Myogenin is essential for the fusion of myoblasts into multinucleated myotubes, a key step in muscle fiber formation. MRF4, also known as myf6, contributes to the maturation and maintenance of muscle fibers. The expression of myogenin and MRF4 is tightly regulated to ensure the proper formation of functional muscle tissue.
