Fig. 4

ID4 is selectively amplified in cancers arising in germline BRCA1 mutation carriers. a ID4 amplification in sporadic and familial BLBC. Example images of fluorescent in situ hybridisation (FISH) analysis of ID4 (red) and CEP6 centromeric control (green) copy number aberrations in a cohort of 42 sporadic BLBCs. 10 μm scale. b Example images of FISH analysis of ID4 (red) and CEP6 centromeric control (green) copy number aberrations in a cohort of 97 BRCA1-mutant BLBCs. 10 μm scale. c Percentage of ID4 amplified cases in sporadic and BRCA1-mutant BLBCs presented in a and b. *p < 0.05 (two-sample t test). d Immunohistochemical analysis of ID4 protein expression in the sporadic and BRCA1-mutant BLBCs presented in a and b. ID4 protein quantified using the H-score method. H-score = intensity of staining (on a scale from 0 to 3) × percentage of cells positive. p = 0.007 (Mann-Whitney two-tailed test). e Example images of FISH analysis of ID4 (red) and CEP6 centromeric control (green) copy number aberrations in a cohort of 97 high-grade serous ovarian cancers. 10 μm scale. f Immunohistochemistry staining for ID4 in HGSOC. Example images of ID4 high expressing (top) and ID4 low expressing (bottom) HGSOC. g ID4 H-score compared with corresponding ID4:CEP6 FISH ratio. Assuming non-Gaussian distribution, H-score and FISH correlated with a value of r = 0.457 and Spearman correlation p ≤ 0.0001