NIS expression was evaluated by immunohistochemistry in human salivary gland tissue microarrays constructed of normal, inflamed, and neoplastic salivary tissue cores. Cumulative123I radioactivity reflecting the combination of NIS activity with clearance of saliva secretion in submandibular and parotid salivary glands was evaluated by single-photon emission computed tomography/computed tomography imaging 24 hours after123I administration in 50 thyroid cancer patients.