CD274 and Hashimoto thyroiditis: Although no reports have ascribed a role to PD-L1 in the onset of thyroid dysfunction including Grave’s disease and Hashimoto’s thyroiditis, PD-L1 deficiency has been associated with the onset and exacerbation of various autoimmune diseases, including type 1 diabetes24,25, rheumatoid arthritis26,27, and ankylosing spondylitis28.