Immunohistochemical evaluation of the expression of ADAM9 protease in normal epithelium, CIN3 lesions, and squamous cell carcinoma of the cervix (50 cases) showed that in the normal epithelium of the cervix, there was weak cytoplasmic expression and membrane staining of ADAM9; pronounced expression of ADAM9 was observed in the foci of CIN3, and to a greater extent in squamous cell carcinomas of the cervix. Here, ADAM9 is linked to cervical squamous cell carcinoma.