Analyzing the sciatic nerves from mice with PDN revealed elevated pro-inflammatory markers of M1 macrophages, such as TNF-α and IL-1β, and reduced anti-inflammatory markers of M2 macrophages, such as IL-10 and transforming growth factor (TGF)-β, and the interference and polarization of macrophages toward the M2 phenotype positively affected the improvement in DM complications [69]. Here, TNF is linked to diabetes mellitus.