Sentence:  This iodoprotein does not appear to be the same as what is normally present in the thyroid , and there is no evidence so far that <WSD>thyroglobulin</WSD> can be iodinated in vitro by cell-free systems . 
Meaning of the word marked with <WSD> tags:  an iodine containing protein that is obtained from the thyroid gland and exhibits the general properties of the globulins