Notably, although KMO activity is elevated in the brain of R6/2 HD model mice [10], we did not see a similar effect here, likely due to neuroinflammation-dependent upregulation of KMO expression in vivo [37] and that the KMO BiFC constructs employed are not under transcriptional control of the endogenous KMO promoter. This evidence concerns the gene KMO and ring chromosome 6.