TNF and diabetic neuropathy: A number of recent studies have identified elevated immune markers (C-reactive protein, tumor necrosis factor alpha (TNF-α), interleukin (IL) 6 (IL-6), toll-like receptor (TLR) 4, transforming growth factor beta 1 (TGF β 1) and the presence of antinuclear and anti-ganglioside auto-antibodies in diabetic neuropathy (Hussain et al., 2013, 2016; Janahi et al., 2015; Zhu et al., 2015; Ge et al., 2016), however these studies do not distinguish between painless and painful neuropathy.