Patients treated with anti-CTLA-4 mAbs (ipilimumab and tremelimumab) had higher risks of hypothyroidism (OR, 7.86, 95% CI, 4.10–15.04) but not hyperthyroidism (OR, 3.78, 95% CI, 0.94–15.17), compared to the control groups receiving a placebo, chemotherapy, radiation therapy, or vaccine. Here, CTLA4 is linked to hyperthyroidism.