TLR4 and cancer: In addition, TLRs sense so-called damage-associated molecular patterns (DAMP), such as extracellular high mobility group box 1 protein (HMGB1), histones and hemoglobin.20, 21 It has been shown that the entire TLR family of proteins and particularly TLR4 is induced by radiation in lymphocytes isolated from healthy subjects.22 In addition, deficiency of TLR4 promotes cancer development through decreased expression of DNA repair proteins leading to impaired DNA repair.23 HeLa cells pre-treated with vehicle or TLR4 inhibitor were irradiated at 9 Gy and cell lysates were made after 2 and 4 h.