Expression studies also showed the development of a retinoblastoma signature and upregulation of specific genes associated with retinoblastoma in late RB1 mutant organoids (Figure 7D and Figure S14) [25,27], since the deviation of differentiation in RB1 knockout organoids became evident only after about 40 days (Figure 5B) [25]. This evidence concerns the gene RB1 and retinoblastoma.