HMGB1 and thyroid cancer: Similar to leukemia (HL-60 & K562) and HBE cells in our previous studies [22, 24], HMGB1 expression was high in all five thyroid cancer cell lines (K1, KTC-1, TPC-1, FTC-133 & FRO) and yet low in normal human thyroid cells HT-ori3 (Fig. 1a).