Table 1.

Array heritability estimated from iCOGS array for invasive EOC, stratified by histotypes

EOC histotype	N case/control (relatedness <0.1)	K	$h_{\mathrm{g}}^2\mathrm{\%}$ (95% CI)
High-grade serous	4121/21 663 (4098/21 242)	0.0055	8.8 (6.8–10.8)
Low-grade serous	363/21 663 (362/21 242)	0.0005	0.0 (0–9.3)
Endometrioid	1350/21 663 (1342/21 242)	0.001	3.2 (0.06–6.3)
Mucinous	662/21 663 (658/21 242)	0.0005	0.0 (0–5.4)
Clear cell	621/21 663 (620/21 242)	0.0005	6.7 (0.3–13.1)
All invasive EOC	10 065/21 663 (10 014/21 242)	0.009	5.6 (4.4–6.7)

N case/control (relatedness <0.1): case/control sample size, and case/control sample size restricting pairwise genetic relatedness between individuals <0.1 (see the Supplementary Material, Table S3, for comparison of results using the cut-off of 0.05); K: disease prevalence of EOC histotype, defined as the lifetime risk of invasive ovarian cancer (∼0.9%, see the Materials and Methods section) times the fraction of the corresponding EOC histotype; $h_{\mathrm{g}}^2$ (95% CI): array heritability and its 95% confidence intervals that were estimated using ovarian cancer iCOGS data, while adjusting for 10 PCs and study sites.