PRC1.1 plays a role in menin inhibitor target repression. (A) Canonical menin targets such as MEIS1 (left) are repressed upon menin inhibitor treatment irrespective of PRC1.1 activity (center and right). (B) Type II menin targets such as MYC show enrichment of both menin and PRC1.1-deposited H2AK119ub (left). In PRC1.1-proficient cells treated with menin inhibitor, these targets are silenced due to the suppression of menin and subsequent repression by H2AK119ub (center). However, in PRC1.1-deficient cells receiving menin inhibitor treatment, the loss of PRC1.1 reduces the H2AK119ub signal, leading to the epigenetic reactivation of these genes (right). Image created with BioRender.com.