For a deeper investigation, we analyzed the circulant levels of factors involved in the NP control [42,43,44] and interestingly, peripheral neuropathy increased circulating SP levels (F(3.20) = 24.63, p = 0.0001; Figure 5A) and decreased β-endorphin levels (F(3.20) = 6.762, p = 0.0021; Figure 5B) when compared to FOP animals. This evidence concerns the gene TFF2 and peripheral neuropathy.