HMGB1 and cancer: Recently, increasing evidence has unveiled the pro-nociceptive role of HMGB1 in the peripheral tissue and spinal cord [16,18,29,80,89], and demonstrated that endogenous HMGB1 is involved in the pathogenesis of various types of intractable pain [11,15], including inflammatory pain [28,29,80], visceral pain [19,20,30,32], neuropathic pain [23,31,76,91,92], cancer pain [33], and post-stroke pain [34].