The results from 26 MDS patients showed that IGF-IR expression on clonal cells was markedly elevated compared with that on normal cells in the same MDS patient (P<0.0001), and the percentage of clonal cells in IGF-IR positive cells was significantly higher than that in IGF-IR negative cells (85.4 vs. 28.5%; P<0.0001) (S2 Fig). This evidence concerns the gene IGF1R and myelodysplastic syndrome.