E Ratio of toxicity and viability measurements of HCT116 spheroids (3D) and 2D cultures, treated as indicated (NEN 1.2 µM, Domperidone 30 µM). Cells were transfected either with control (siCtrl) or UPP1-targeting (siUPP1) siRNAs prior to spheroid formation or during cell seeding. Data information: data (N=3) are presented as mean (SD) and were analyzed by two -way ANOVA with Tukey post-hoc test 