We carried out immunohistochemical staining using anti-Iba-1 antibodies on tissue sections of spinal cord obtained from specimens of 3 experimental groups, and compare spatial distribution pattern of Iba-1-positive microglial cells (Fig. 4, Supplementary Figure 1a), since it is well established that peripheral nerve injury-induced hyperalgesia involves proliferation and morphological hypertrophy of microglia in the central nervous system26,27. Here, AIF1 is linked to peripheral nerve injury.