Interestingly, CD133, also known as PROM1, is expressed at increased levels in acute myeloid leukaemia (AML) HSCs and has been documented as a marker of cancer stem cells (CSCs) in several human neoplasms, and its expression seems to predict unfavourable prognosis30, corroborating the hypothesis that increased SLPI may contribute to the leukaemogenesis process. This evidence concerns the gene PROM1 and acute myeloid leukemia.