Expression of motif-corresponding candidate transcription factors. (A) Shown are mRNA expression profiles for members of the bHLH-ZIP, IRF, and zinc finger gene families based on published microarray data for HSCs, MOs, and MACs.²¹  (Expression profiles for the bZIP, ETS, HOX, E2F, RUNX, and GATA gene families are found in supplemental Figure 3.) Classification of transcription factors is based on the properties of their DNA-binding domains (http://www.edgar-wingender.de/TFclass.html). Only genes with detectable expression are shown. Cell types are indicated by coloring (HSCs, purple; MOs, dark red; MACs, blue). (B) Western blot analysis of candidate transcription factor protein expression during human monocytic differentiation in vitro.