One study has shown that the overexpression of the serine protease HTRA-1 is responsible for the prevention of cell proliferation in cervical HPV-negative cell lines and increasing cell proliferation in cervical HPV-positive cells, inferring that HTRA-1/E6 interaction is the underlying mechanism for the bypassing of growth arrest in HPV-positive cervical cancer cell lines [120]. Here, HTRA1 is linked to cervical cancer.