CD33 and acute myeloid leukemia: Haubner and coworkers explored the expression levels of surface LSC markers CD123, CD33, CLL1, TIM3, CD244, and CD47 in a large cohort of 356 AML patients at diagnosis, and in 54 of these patients at relapse; CD123, CD244, CLL1, and TIM3 were expressed both at diagnosis and at relapse [32].