AML (including STAG2-mutant) cell lines were sensitive to PARPi both in vitro and in vivo (xenograft model).Primary STAG2-mutant AML samples exhibited dose-dependent sensitivity to PARPi. PARPi depleted cohesin-mutant clones in a Tet2/Stag2-mutant murine model of MDS/AML. Here, TET2 is linked to myelodysplastic syndrome.