To look at this more closely, we compared the nucleotide sequences at the location of the aberrant 3′ splice sites identified in human SF3B1-mutant cancers,11, 13 including MDS, and those identified in our Sf3b1K700E/+ mouse BM and lin− cells with the equivalent positions in the genome of the other species, examining the conservation of the invariant AG dinucleotides at the splice sites and that of the upstream 35nt. This evidence concerns the gene SF3B1 and cancer.