André F. Carvalho’s research while affiliated with University of Toronto and other places

... Consequently, the KYN pathway is tightly regulated by cytokines, which can either enhance or suppress its activity depending on the body's inflammatory state (18). In chronic conditions, sustained elevation of inflammatory cytokines leads to excessive activation of this pathway (19)(20)(21). This overactivation leads to an increase in the production of neurotoxic metabolites, such as 3HK and QUINA (see Figure 1). ...

Reference:

Exercise-induced adaptations in the kynurenine pathway: implications for health and disease management