EZH2 inhibitor UNC1999 enhanced PARP1 inhibitor olaparib-mediated synthetic lethality in BRCA-deficient cell lines and acute myeloid leukemia (AML) primary cells (A) BRCA1 -mutated and BRCA1 -reconstituted MDA-MB-436 human breast carcinoma cells were treated with or without the PARP1 inhibitor olaparib in the presence or absence of the EZH2 inhibitor UNC1999 at the indicated concentrations. After 4 days, cell count/viability was determined by Trypan blue exclusion using a Bio Rad TC20 Automated Cell Counter. Results show mean ± SD of living cells. N=3. * p