In this sense, knowledge of the involvement of KP in MS has essentially two potential clinical applications: (1) kynurenines serve as biomarkers of disease activity, markers of therapeutic responses or markers that allow the identification of clinical endophenotypes of the disease, which in turn allow the development of more individualized and effective treatments; and (2) they provide new therapeutic targets; it is precisely these types of therapeutic trials based on KP modulation that may potentially further support the role of KP in MS [129]. Here, NPPA is linked to myeloid sarcoma.