CD44 and retinoblastoma: The co-expression of EpCAM+CD44+, EpCAM+CD24+, and EpCAM+ABCG2+ ranged from 0.83% to 42.6%, 0.65% to 41.4%, and 1.6% to 6.5%, respectively, in the eight RB tumor samples (Figure 3, Figure 4, Figure 5, Figure 6, Figure 7, Figure 8, Figure 9, and Figure 10).