PROS1 and squamous cell carcinoma: Our data indicate that the co-expression of the LMP1 and E6 onco-proteins of EBV and high-risk HPVs, respectively, is associated with poorly differentiated squamous cell carcinoma form (Figure 2) in comparison with HPVs positive cases alone as well as negative cases for both, EBV and HPVs (p < 0.0001, respectively).