Further analysis of other Pbx family members (including Pbx2 and Pbx3) revealed that Pbx4 was also exclusively upregulated in leukemic BM (Fig. 2b; Supplementary Fig. 4a), similar to Pbxip1. These findings were consistent with RNA-Seq data from pediatric t(7;12) AML samples in the COG-NCI TARGET dataset (Supplementary Table S8), where both PBXIP1 and PBX4 were upregulated compared to normal BM (Fig. 2c). Here, PBX3 is linked to acute myeloid leukemia.