BACKGROUND: Persistent inflammation leading to neuronal sensitization in pain pathways, are key features of chronic inflammatory pain. Alike macrophages in the periphery, glial cells exacerbate hypersensitivity by releasing proalgesic mediators in the central nervous system. Expressed by peripheral and central immune cells, the cystine-glutamate antiporter system x METHODS: Complete Freund's adjuvant (CFA) was injected into the left hind paw of wild-type C57Bl/6 female mice, of xCT-deficient mice (specific subunit of system x RESULTS: CFA injection led to a persistent increase in paw edema and hypersensitivity to mechanical and thermal stimuli, which were less pronounced in xCT-deficient mice. This reduced sensitivity was accompanied by lower systemic pro-inflammatory cytokine levels in xCT-deficient mice. Accordingly, pharmacological inhibition of system x CONCLUSION: Our findings reveal a critical role for system x