Proteomic Analysis Identifies Association of Periostin, a Matricellular Protein, with High Tumor Stroma and Immune Exclusion in Triple-Negative Breast Cancer

Periostin is overexpressed in stroma high, immune excluded TNBC and is derived from CAFs. Its expression is associated with reduced TILs and poor prognosis. The development of targeted agents against periostin-positive CAFs may help overcome immune evasion and improve the effectiveness of immunotherapy in TNBC.