CD274 and oral cavity neoplasm: The bTMB ≥ 16 mut/Mb subgroup was enriched for patients who had PD-L1 expression TC ≥ 25% or poorer performance status, and included fewer patients with oral cavity tumors, more patients with laryngeal tumors, and more patients with metastatic versus recurrent disease, compared with the bTMB < 16 mut/Mb subgroup (Supplementary Table 4).