CXCR4 and diabetes mellitus: Moreover, daily oral administration of NAC improved nociceptive behaviors in the late stage (5 weeks of diabetes) as assessed by PWT and PWL and significantly reduced the expression of CXCR4 in the spinal cord dorsal horn of rats with DNP (Figure 5, P < 0.05, Dia vs. NAC; Figure 6(h), P < 0.05, Dia vs. NAC).