This profile for UTUC‐4_O is typical in urothelial carcinoma.[22] Five UTUC organoids and their corresponding tumors exhibited positive staining for the luminal marker GATA3 and the urothelial marker cytokeratin 20 (CK20) and these were conserved between the organoids and their tumor sources. Here, GATA3 is linked to urothelial carcinoma.