Increased RAD51 mRNA expression levels are correlated with worse prognosis in HPV(+) HNSCC tumors; the combination of a RAD51 inhibitor with a Wee1 inhibitor has been shown to significantly inhibit tumor growth in mice with HPV(+) HNSCC tumors, as compared to mice with HPV(−) HNSCC, suggesting that HPV(+) tumors may be more dependent on DDR mechanisms in order to counteract the effects of increased replication stress (due to the transformation by the viral oncogenes E6 and E7) [151]. Here, RAD51 is linked to head and neck squamous cell carcinoma.