DCK and acute lymphoblastic leukemia: Even though no inactivation of dCK could be demonstrated in vivo in cytarabine resistant primary AML cells, a phase I-study with 17 pediatric patients with relapsed acute lymphoblastic leukemia (ALL) after high-dose cytarabine treatment yielded a complete remission in two out of 9 evaluable patients after treatment with azacitidine followed by another course of high-dose cytarabine [13].