ATP5PO and hypothyroidism: ATPO-negative individuals had higher radiation-related risk of hypothyroidism (EOR/Gy = 0.40; 95% CI: 0.19, 0.74) than ATPO-positive individuals (EOR/Gy = –0.19; 95% CI: –0.38, 0.42) but the difference was of borderline statistical significance (p = 0.06).