First, we studied the expression of 12 oncogenes and tumour suppressor genes involved in splicing using a Fluidigm array (Figure 1 and Figure S1) in progenitor cells (CD34+CD15− sorted cells) from 15 patients diagnosed with CP-CML (patient 1 to 15, Supplemental Table S1) and in similar cell subsets from 10 healthy donors (HD). Here, FUT4 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.