TNFRSF1A and neoplasm: However, there is still debate regarding the relative roles of TNFR1 and TNFR2 in chronic pain: in mice with tumor-induced thermal hyperalgesia, deletion of the TNFR2 gene reduces the painful response hence signifying a role for TNFR2 [89]; whilst in rats with spinal root injury, TNFR1 elicits excitatory responses in DRG of adjacent uninjured roots and TNFR2 excites DRG neurons from injured roots [90].