Fusion positive RMS demonstrate strong myogenin (A, 200x), AP2β (B, 200x), and NOS-1 (C, 200x) expression with weaker or absent HMGA2 expression (D, 200x). In contrast, fusion negative RMS demonstrate weak to moderate myogenin expression (E, 200x), weak or absent AP2β (F, 200x) and NOS-1 (G, 200x) expression and strong HMGA2 expression (H, 200x).