Of note is that, with regards to arthritic diseases, the association of SFN and UA was never described before, except as a complication of anti-TNF-α treatment in rheumatoid arthritis patients who presented a pain distribution often not conforming to the traditional “stocking-and-glove” pattern [35], and generally attributed to the cross-linked immunological reactions to treatment [36]. The gene discussed is TNF; the disease is rheumatoid arthritis.