PROM1 and acute lymphoblastic leukemia: Consequently, targeting PROM1/CD133-positive cells has been proposed as a therapeutic option for KMT2A-rearranged ALL, although the expression of PROM1/CD133 on both fetal and adult hematopoietic stem cells (HSCs) may compromise the specificity of such an approach [29, 30, 53, 54].