PTEN and T-cell leukemia: Accordingly, the present study explores amino acid transport in a mouse model of T-cell leukemia/lymphoma where thymic deletion of the inositol phosphatase PTEN drives rapid T leukemogenesis/lymphomagenesis.25, 27, 28 We show that PTEN-null malignant T cells have high membrane transport capacity for multiple nutrients including high System L amino acid transporter activity driven by NOTCH signaling pathways.