Figure 1. Representative light microscopy pictures of staining of B lymphoma Mo-MLV insertion region 1 (BMI-1) antigen in undifferentiated retinoblastomas grouped according to Tumor, Nodes, Metastasis (TNM) classification. A: Retinoblastoma sections were stained by hematoxylin and eosin.B: Magnified images in C: intense nuclear BMI-1 expression in undifferentiated retinoblastomas. Scale bars: 50 µm.