KMO and Huntington disease: A study in R6/2 mice, modeling HD, also demonstrated the increased activity of KMO (1.65‐fold change in vmax value between 8‐week‐old wild‐type and R6/2 animals) and decreased activity of kynureninase (−1.5‐ to −1.67‐fold), resulting in an excessive enzymatic conversion of tryptophan to 3‐HK.133