Consistently, astrocyte reactivity and microglial activation also increased throughout the main tumour mass in WT npp tumours, although the former was more pronounced than the latter outside the injury site (Fig. 4d–f and Extended Data Fig. 5d–f); in npp tumours generated in Sarm1−/− mice at both timepoints, injury-induced inflammation was significantly reduced compared with the WT at the site of injury and was fully abolished in the rest of the tumour (Fig. 4d–f and Extended Data Fig. 5d–f). This evidence concerns the gene SARM1 and neoplasm.