As the chaperon-like prodomain of ADAM33 binds to the catalytic domain to inhibit its proteolytic activity, we hypothesized that ADAM33-n is a natural inhibitor of full-length ADAM33 and that the downregulation of ADAM33-n consequently restores the oncogenic function of ADAM33 in thyroid cancer (Fig. 4A). Here, ADAM33 is linked to thyroid gland carcinoma.