KMO's activity can be used to clinical diagnosis, and more and more researchers have also found that KMO is a therapeutic target for the treatment of central nervous system diseases, especially Huntington's disease, but basically focuses on the mechanism of KMO in the microglia in the brain, and less on effects of KMO in peripheral organizations (Sathyasaikumar, Breda, Schwarcz, & Giorgini, 2018). This evidence concerns the gene KMO and Huntington disease.