TPO and thyrotoxicosis: A similar clinical case was presented by Hakami in 2019 [13] — the development of type 1 diabetes and hypothyroidism in a 52-year-old man during monotherapy with pembrolizumab. At the same time, the first damage to the thyroid gland (thyrotoxicosis, TSH 0.09 mIU/l) developed after the second injection of the drug, followed by the formation of persistent hypothyroidism (anti-TPO antibodies negative) after the fifth injection of pembrolizumab.