TGFB1 and adult T-cell leukemia/lymphoma: On the contrary, ZEB1 is a candidate tumor suppressor gene in adult T-cell leukemia/lymphoma (ATLL), where it contributes to TGF-β1-mediated growth suppression resistance of malignant CD4+ T cells and ZEB1 mutant mice frequently undergo spontaneous CD4+ T-cell lymphomas20,21.