ZNF251 and breast cancer: To collect more evidence to support our finding, we also performed bioinformatic analysis of previously published PARPi resistance studies and found significantly lower expression of ZNF251 in two olaparib-resistant breast cancer cell lines (MDA-MB-468 and SUM1315 lines) when compared to their sensitive counterparts (Supplementary Fig. 4A)13·14, showing that low expression of ZNF251 is correlated with olaparib resistance.