BRCA1 and ovarian cancer: Indeed, BRCA1 mutant ovarian cancer cell lines were the most sensitive to [125I]KX1; however, dosimetric analysis revealed interesting differences in RBE, which suggests [125I]KX1 is more effective than low-LET beta-emitting analogue [131I]KX1 in ovarian cancer cell lines with functional BRCA1. We propose that increased DNA repair capacity of ovarian cancer cell lines provides a better cellular fitness capable of mitigating DNA damage induced by low-LET radiation, whereas a known property of high-LET radiation is that cell kill effects are independent of DNA repair capacity.