To further elucidate the mechanism of the TLR4/NF-κB signaling axis in arsenic-induced thyroid injury in SD rats, we administered the TAK-242 intervention to arsenic-exposed rats, resulting in significantly reduced expression levels and phosphorylation of the TLR4/NF-κB signaling axis-related proteins in thyroid tissue compared to the AsIII-exposed group. Here, NFKB1 is linked to thyroiditis.