Furthermore, depletion of OGG1, PARG, Pol β, or XRCC1 had no impact on the radiosensitivity of HNSCC cells, specifically UMSCC74A (Supplementary Fig. 2E–H), UMSCC6 (Supplementary Fig. 2I–L) and FaDu (Supplementary Fig. 2M–P), to X-rays. Here, XRCC1 is linked to head and neck squamous cell carcinoma.