CXCR2 and head and neck squamous cell carcinoma: Furthermore, the radiosensitizing effect was not attributable to increased DNA damage, as evidenced by γH2AX/53BP1 co-localization.<h4>Conclusions</h4>These findings highlight a central role for CXCR2-mediated signaling in the development of radioresistance in HPV-negative HNSCC cells.<h4>Clinical trial number</h4>Not applicable.