When the oncoproteins are highly abundant, PC1-specific oncoprotein-target genes, such as FLT3 and TAPT1, are consistently bound by the B-ALL-enriched MLL::AF4 and MLL::ENL fusion proteins (Fig. 4a–c, Supplementary Fig. 4i). The gene discussed is KMT2A; the disease is precursor B-cell acute lymphoblastic leukemia.