We successfully genetically targeted one very well-established tumor suppressor (Trp53) and one recently identified tumor suppressor in urothelial carcinomas (Stag2) in murine basal bladder organoids with Cas9 and gRNAs (guide RNAs) targeting the Trp53 and Stag2 genes. This evidence concerns the gene STAG2 and urothelial carcinoma.