Following these criteria, ten of the circRNAs with validated upregulation in B-cells, T-cells or in both lymphocyte populations (Fig. 2d) were selected for quantification in BCP-ALL, including circRNAs from known genes (AFF2, AFF3, BCL2, FBXW7, IKZF1, IL4R, PAX5, SETBP1 and ZCCHC7) and the newly identified circX(intergenic) highly expressed in lymphocytes. This evidence concerns the gene IKZF1 and acute lymphoblastic leukemia.