This reduction was associated with a significant inhibition in growth, which was reduced from 60 to 80% in WERI Rb1 (Supplementary Figure S4B) and by about 50% in Y79, as found by CCK-8 assay (Supplementary Figure S4C), further supporting a role for ligand-driven Notch signaling in promoting retinoblastoma growth. Here, RB1 is linked to retinoblastoma.