ERBB2 and breast cancer: Based on the consistent efficacy of PARP inhibitors shown in gBRCA1/2mut, HER2- BC, and the promising results observed in phase 1 trials for fuzuloparib with or without apatinib in gBRCA1/2mut BC [19], we have initiated a phase 1/3 trial (NCT04296370) to assess fuzuloparib with or without apatinib, compared to investigator's choice of chemotherapy, in the treatment of gBRCAmut, HER2- BC.