ESR1 and leukemia: Out of 35 genes in Module 2, 14 (Additional files 6 and 7) are associated with regulation (either positively or negatively) of cell proliferation, including Bcl11b, Flt3, Gata3, Cdkn1a, Cdkn2a, Tek, Esr1, Pbx1, Cdkn2b, APC, Tcf7, Tgfb2, Tgfb3, and Mycn. Among these genes, Pbx1 is especially important because it has been shown to be a critical gene required in leukemia initiation [52,53].