CTLA4 and hypothyroidism: A meta-analysis has shown that patients treated with anti-programmed cell death protein 1 (c) combined with anti-cytotoxic T-lymphocyte antigen 4 (anti-CTLA-4) had the highest incidence of hypothyroidism and hyperthyroidism, patients treated with anti-PD1 alone were at even higher risk of hypothyroidism, and patients treated with anti-CTLA-4 alone were at even higher risk of developing pituitary inflammation (2).