Knockout of the ING5 epigenetic regulator confirms roles in stem cell maintenance and tumor suppression in vivo.

INhibitor of Growth (ING1-5) proteins are epigenetic readers that target histone acetyltransferase (HAT) or histone deacetylase (HDAC) complexes to the H3K4Me3 mark of active transcription. ING5 targets Moz/Morf and HBO1 HAT complexes that alter acetylation of H3 and H4 core histones, affecting gene expression. Previous experiments in vitro indicated that ING5 functions to maintain stem cell character in normal and in cancer stem cells.