CD274 and head and neck cancer: On the immune axis, tumor-infiltrating PD-L1+ neutrophils suppress T-cell function in head and neck cancer via GM-CSF–driven programs (23), and the PD-L1/PD-1 checkpoint directly restrains neutrophil cytotoxicity in cancer (22); in OSCC, neutrophils further promote tumor progression through Chemerin–JAK2/STAT3 signaling (30).