HMGB1 and retinoblastoma: Although heat shock proteins 70/90 (HSP70/90), adenosine triphosphate (ATP) and high mobility group box 1 (HMGB1) are released during ICD in addition to the critical signal molecule CRT; the mechanisms underlying RB-induced ICD are still unknown and may be related to the role of ER stress and reactive oxygen species (ROS) [37].