Kdm2b maintains murine embryonic stem cell status by recruiting PRC1 complex to CpG islands of developmental genes

How polycomb group proteins are recruited to lineage specific genes to repress their expression in mouse embryonic stem cells has been unclear. Zhang and colleagues show that the histone lysine demethylase Kdm2b recruits Ring1 of the PRC1 complex to a subset of these targets, through a non-catalytic domain. The expression of Kdm2 is also shown to be regulated by the pluripotency factors Oct4 and Sox2.