PBX1 and cancer: By further calculating expression level measured as fragments per kilobase of exon per million mapped fragments (FPKM; Methods) of the corresponding C’ genes (Supplementary Fig. 5c), we confirmed that RUNX1T1 in RUNX1-RUNX1T1, PBX1 in TCF3-PBX1, GLIS2 in CBFA2T3-GLIS2, and AFDN in KMT2A-AFDN have FPKM < 1 and are considered non-expressed in the normal lineage of corresponding cancer subtypes (blue asterisks in Fig. 3b).