Impairment of HR by WEE1 inhibition was instead responsible for the synergism with olaparib in AML (MV4-11; KMT2A-MLLT3 rearranged AML cell line, MOLM13; NPM1/DNMT3A double mut AML cell line, OCI-AML3) and ALL (ETV6-RUNX1 rearranged pre B-ALL cell line, REH) cell lines, resulting in DNA damage accumulation and cell death by apoptosis, as also confirmed in an AML murine model [107]. Here, MLLT3 is linked to acute lymphoblastic leukemia.