Runx1 locus and isoforms. (A) Schematic of the 224-kb mouse Runx1 locus, alternative splice forms, and the +23 enhancer (not to scale) reported in the literature.^{46,108,109,114,128,142,143}  White boxes, coding sequence; red boxes, untranslated regions (UTRs); blue box, predicted coding +UTR. Figure 3A reprinted with minimal alteration from Bee et al⁴⁶  with permission from Elsevier. (B) Schematic showing Runx1 protein domains relative to their coding exons.¹¹⁰  CDS, coding sequence; ID, inhibitory domain; RD, runt domain; TAD, transactivation domain.