CD276 and head and neck squamous cell carcinoma: This study aimed to (i) identify the relationship of TME and B7-H3 expression in HNSCC; (ii) evaluate its prognostic value; (iii) exploit B7-H3 as a biomarker that predicts the response of immune checkpoint therapy; (iv) elucidate the potential signaling pathways of HNSCC in the development and progression of HNSCC.