srf is important during the development of the embryo, as it has been linked to the formation of mesoderm. in the fully developed mammal, srf is crucial for the growth of skeletal muscle. interaction of srf with other proteins, such as steroid hormone receptors, may contribute to regulation of muscle growth by steroids. interaction of srf with other proteins such as myocardin or elk-1 may enhance or suppress expression of genes important for growth of vascular smooth muscle.