Next, we tested the PARPi vulnerability of Asxl1−/−Ezh2−/− cells using another new Asxl1−/−Ezh2−/− Runx1KD mouse model that mimic RUNX1 haplodeficiency frequently coexisting with the PcG LoF mutations in patients with MDS.1 The gene discussed is RUNX1; the disease is myelodysplastic syndrome.