Furthermore, STAT3 has been shown to be a critical mediator of HPV E6-induced tumour formation in vivo: STAT3 knockdown by shRNA resulted in reduced tumour growth in both HPV+ cervical cancer mouse xenografts and E6-expressing HPV- cervical cancer cell xenografts [154], demonstrating that STAT3 may be an attractive therapeutic target in cervical cancer. Here, STAT3 is linked to cervical cancer.