CTPS2 and Sezary syndrome: CTPS2 was not detectable or weakly expressed in some cancer cell lines of T lymphoid origin like MOLT-4 (a human T lymphoblast line from an acute lymphoblastic leukemia), HUT-78 (derived from cutaneous T lymphocytes from a patient with Sezary syndrome), and Jurkat (an acute T-cell leukemia) cells, whereas it was detectable in CCRF–CEM cells, an acute lymphoblastic T-cell leukemia/T-ALL (Fig 1A).