ADAM9, as an important member of this family, is widely distributed in human tissues and involved in various biological processes.36, 37 ADAM9 is highly expressed in multiple cancers and is related to aggressive tumor phenotypes and poor clinical outcomes.36 ADAM9 has been found to be responsible for the growth and metastasis of thyroid cancer.27 We found that ADAM9 expression was higher in PTC tissues and cells than their controls. Here, ADAM9 is linked to thyroid cancer.