CD274 and neoplasm: Single-cell–grounded signatures and immunohistochemical surrogates for SPP1+ tumor-associated macrophages correlate with immunosuppressive programs, matrix remodeling, and inferior outcomes in head and neck and oral cavity cohorts, nominating an “SPP1–TAM burden” as a candidate readout to complement PD-L1 and tumor mutation burden in clinical decision-making (78, 79).