Normal retina and retinoblastoma (A) Thin section of normal murine retina with outer nuclear (ONL), inner nuclear layer (INL) and ganglion cell layer (GCL) shown. (B) Hematoxylin and Eosin (H+E) stain of human retinoblastoma with neuroblastic differentiation and Homer-Wright (HW) rosettes. (C) H+E staining of human retinoblastoma exhibiting Flexner-Wintersteiner (FW) rosettes. Inset: M-opsin immunostaining showing evidence of cone differentiation. (D) H+E of primary murine retinoblastoma lacking Rb and p130 with Homer-Wright rosettes indicated.