HMGB1 and thromboangiitis obliterans: The first conclusion, based on the 25-fold change higher gene expression of HMGB1 in the SG of TAO patients and also the high gene expression of TLR9, without any change in the gene expression of TLR4 or RAGE, could indicate a sterile and reactive inflammation in the SG in response to the release of mtDNA to the cytoplasm.