H Ratio of toxicity and viability of HCT116 spheroids (3D) treated as indicated (NEN 1.2 µM, Imipramine (Imi), Desipramine (Desi), Amitriptyline (Ami), each 30 µM). Cells were transfected with control (siCtrl) or UPP1-targeting (siUPP1) siRNAs 24h prior to spheroid formation. Data information: data (N=3) are presented as mean (SD) and were analyzed by two -way ANOVA with Tukey post-hoc test 