BTG3 and amyotrophic lateral sclerosis: When comparing KP levels group-to-group, we observed significantly lower neostriatal 3-HK, KYN, KYNA, XA, QUIN, PA, ANA levels and KYN/TRP ratios in ALS compared to FTD, EOAD and control subjects, although differences in PA and ANA levels did not remain significant following multiple comparison correction between ALS and control subjects.