PTEN and neoplasm: Next, we investigated the potential effects of KMT9 ablation in tumor organoids derived from mice harboring alleles flanked with the following loxP sites: Ptenfl/fl/Trp53fl/fl (resulting in Pten/Trp53 KO organoids after the Cre-induced deletion of alleles), Ptenfl/fl/Trp53fl/fl/Kmt9αfl/fl (resulting in Pten/Trp53/Kmt9α KO organoids), and Ptenfl/fl/Trp53fl/fl/Kmt9αN122AflKI/flKI (resulting in Pten/Trp53 KO organoids with knock-in (KI) of the catalytically inactive mutant KMT9αN122A).