Figure 1.

Major pathways involved in neurological diseases with confirmed or suspected neuroinflammation – tryptophan–kynurenine pathway (right above), nitric oxide pathway (left bottom), neopterin (right bottom) and sphingolipid–ceramide pathway (left above). Trends are highlighted in red (representing statistically elevated in patients with neuroinflammation compared with controls) and blue (representing statistically decreased in patients with neuroinflammation compared with controls). Neopterin is the most valuable inflammatory metabolite in the GTP–tetrahydrobiopterin metabolism; therefore, the full pathway is not shown. 3‐HAO, 3‐hydroxyanthranilic acid oxygenase; ADMA, asymmetric dimethylarginine; CerS, ceramide synthase; DEGS, dihydroceramide desaturase; GTPCH I, guanosine triphosphate cyclohydrolase I; IDO, indoleamine 2,3‐dioxygenase; IFN‐γ, interferon‐gamma; KAT, kynurenine aminotransferase; KMO, kynurenine monooxygenase; KSR, ketosphinganine reductase; KYNU, kynureninase; NO, nitric oxide; NOS, nitric oxide synthase; SMases, sphingomyelinases; SPT, serine palmitoyltransferase; TDO, tryptophan 2,3‐dioxygenase.