ENTPD1 and complex regional pain syndrome: This idea is partially supported by the findings in the study by Heyn et al. in which the authors found a significantly lower percentage of proinflammatory Th17 cells, a lower Th17/Treg ratio, and a significantly higher proportion of anti-inflammatory CD39+Tregs in a group of CRPS patients, suggesting an anti-inflammatory T-cell shift in CRPS [9].