WWTR1 and neoplasm: Tumor formation in vivo was observed in the majority of mice (4 out 5) when E10-TAZ-S89A-T cells were injected, whereas knockout of Aldh1a1 in E10-TAZ-S89A-T cells (E10-TAZ-S89A-sgAdhl1a1) completely abolished tumor seeding and growth in mice (Table 1).