MKI67 and head and neck cancer: Based on the existing knowledge about the molecular biology of head and neck cancers associated with high-risk HPV infection, one would expect HPV-driven tumors to show positive reactions in HPV-DNA-PCR, HPV-DNA-ISH, and p16-Ki67 dual stain, as well as high expression levels for p16 with low expression levels of Cyclin D1 and pRb.