EGF response factor 1 is a zinc-binding protein encoded by the immediate-early response gene, Zfp-36. TIS11B, a relative of TTP, localizes to the nucleus and may function as a transcription factor involved in regulating the growth factor response. It is an evolutionarily conserved protein containing two C3H1-type zinc fingers and a repeating cys-his motif. TIS11B is an mRNA binding protein and is known to interact with the 3’-untranslated region of VEGF mRNA, thereby decreasing its stability. This suggests that TIS11B is a potential target in antiangiogenic therapy. In addition, TIS11B may also be an important regulator of myogenesis, as its expression is upregulated during murine myoblast differentiation.