RBL2 and retinoblastoma: RB1 expression was significantly low in unilateral Rb compared to bilateral, advanced, and non-advanced Rb groups (Figure 6F), while its pocket protein family gene RBL2 (p130) [42] was significantly low in the bilateral and unilateral Rb groups, and in the advanced and non-advanced Rb compared to the pediatric controls (Figure 6H).