Epigenetic demarcation of Ikzf1 regulatory regions. The location of 10 previously described lymphoid-specific DHS clusters¹⁶  and noncoding regions with extensive mouse-human sequence conservation are shown at the Ikzf1 locus. Individual DHS and DHS clusters are indicated by short vertical bars or red bars. On the Ikzf1 locus, the untranslated exons 1a and 1b associated with distinct promoter activities are denoted as unfilled rectangles and the 7 translated exons 2 to 8 as solid rectangles. Enrichment peaks for histone H3 modifications (H3K4me1, me2, me3, H3K9/14Ac, and H3K36me3) and for the RNA Pol II (pII) initiation (8WG16) and elongation (S5, S2) forms at the Ikzf1 locus are displayed by the Integrative Genomics Viewer (IGV) 2.1 using the mouse genome database mm9. Enrichment peaks for H3K27Ac and p300 were deduced from ENCODE data (supplemental Table 8).²⁰