Mutational analysis of the SF3B1 gene in haematopoietic stem/progenitor cells reveals that SF3B1 mutations arising in phenotypically defined CD34+CD38−CD45RA−CD90+CD49f+ stem cells therefore unveil the MDS-ICs existence in RARS that propagate mutations to their myeloid progenitors, such as MPPs, GMPs and MEPs. This evidence concerns the gene SF3B1 and myelodysplastic syndrome.