The expression of FKBP51 in Hoffa’s fat pad nerves (Figure 6) may show a point for therapy, furthermore, considering that some studies show that when Hoffa’s fat pad was completely removed during total knee arthroplasty for osteoarthritis or rheumatoid arthritis, those patients presented with a higher rate of persistent pain one year after surgery [56]. The gene discussed is FKBP5; the disease is rheumatoid arthritis.