TLR4 and breast cancer: In animal models of thymoma and breast cancer, dendritic cells have been shown to be important in the antitumor T-cell-mediated immune response following radiotherapy through radiation-induced release of high-mobility group box 1 (HMGB1) by dying tumor cells, which act on toll-like receptor 4 (TLR4) expressed by dendritic cells, aiding in processing and cross-presentation of tumor-associated antigens to CD8+ T cells.