Next, to compare the splicing gene expression profile of immature and mature CP-CML cells, we analysed the same 12 splicing genes in immature CP-CML CD34+CD15− cells (n = 15 patients) and mature CP-CML peripheral blood leukocytes (PBL; n = 19 patients; not paired with the other group; see Material and Methods) (patient 29 to 47, Supplemental Table S1). Here, FUT4 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.