Genetic Screens Reveal FEN1 and APEX2 as BRCA2 Synthetic Lethal Targets

？ BRCA2-mutant cells rely on BER, ATR signaling, splicing, and MMEJ for survival ？ APEX2 and FEN1 represent potential drug targets in BRCA-mutant tumors ？ BRCA-mutant cells require the endonuclease function and PCNA association of APEX2 ？ A cell-based reporter demonstrates that FEN1 participates in MME