In contrast to the discrepancy in DRG pathogenesis, spinal microgliosis observed in Tat(+) mice is also present in gp120-induced neuropathy.70,71 Activation of spinal microglia has been described in other neuropathy models characterised by epidermal nerve fibre loss including nerve injury–induced and diabetic neuropathy and is believed to play an important role in the maintenance of neurological complications such as neuropathic pain.13,22,77 Here, spinal astrocyte activation was not shown in spinal cords of Tat(+) mice. This evidence concerns the gene ITIH4 and diabetic neuropathy.