Immunostaining of organoids revealed that a significant reduction in the proportion of proliferative tumor cones (RXRG+ Ki67+: RXRG+) was observed after treatment of RB170 organoids with sunitinib (49.29% ± 2.02%, mean ± SEM) compared with vehicle (62.71% ±1.57%), topotecan (57.43% ±1.67%) and melphalan (65.46% ± 1.23%; Fig. 5D–H). This evidence concerns the gene MKI67 and neoplasm.