The combined treatment was more effective in reducing viable cell concentration and increasing apoptosis than either agent alone in both WERI Rb1 (Figure 7A–7C) and Y79 (Figure 7D–7F) lines, reinforcing the role of Notch signaling in promoting retinoblastoma cell survival and growth, and indicating potentiality for a combined regimen. This evidence concerns the gene RB1 and retinoblastoma.