RELA and autoimmune thyroid disease: Thus, it has been shown that transcription of thyroid peroxidase (TPO), a specific enzyme of differentiated thyroid follicular cells involved in the iodine organification process and one of the most common antigens linked to thyroid autoimmunity, is induced by lipopolysaccharide (LPS) through NF-κB p65/RelA phosphorylation of serine 536.