Pro-inflammatory cytokines, interleukin (IL)-6, IL-8, tumor necrosis factor-α (TNF-α), IL-12, IL-18 and IL-1β, and the anti-inflammatory cytokine IL-10 have been demonstrated to be highly expressed in PC patients, compared to healthy individuals [4,164,165,185,186,187]. This evidence concerns the gene TNF and pachyonychia congenita.