Studies in patients with MS using first-generation and second-generation TSPO radioligands reported focally increased TSPO radioligand uptake associated with gadolinium-enhancing lesions (23, 24), some T2-hyperintense lesions (19, 25), in the thalamus (23, 25), and in some cortical gray matter areas, particularly in patients with secondary progressive MS (26). This evidence concerns the gene TSPO and myeloid sarcoma.