TPO (thyroid peroxidase) is an enzyme essential for thyroid hormone biosynthesis, catalyzing the iodination and coupling of tyrosine residues in thyroglobulin to produce thyroid hormones T3 and T4. The enzyme functions through peroxidase activity at the plasma membrane, facilitating the oxidative processes required for thyroid hormone synthesis 1. TPO serves as a major thyroid autoantigen, with anti-TPO autoantibodies being the most sensitive diagnostic marker for chr2 thyroiditis, present in 85-90% of patients with autoimmune thyroid disease 2. The detection of anti-TPO antibodies is crucial for diagnosing autoimmune thyroid diseases and monitoring treatment efficacy 3. TPO gene mutations are the most commonly reported pathogenic variants in congenital hypothyroidism caused by thyroid hormone synthesis disorders 1. Functional studies demonstrate that TPO mutations can cause developmental defects and disrupt thyroid axis gene expression, affecting multiple components of thyroid hormone regulation including thyroglobulin, deiodinases, thyroid hormone receptors, and TSH signaling 1. The clinical significance of TPO extends beyond thyroid function, as anti-TPO antibody testing has been developed into point-of-care diagnostic tools with sensitivity and specificity comparable to conventional ELISA methods 3.