Among people with MS, higher sGFAP associated with higher volume of chronic lesions with increased TSPO activity (r = 0.36, p = 0.0011) and with thalamic TSPO activity (r = 0.30, p = 0.0069), as well as with T1 and T2 lesion loads (r = 0.38, 0.41, p = 0.0005, 0.0002, respectively). This evidence concerns the gene TSPO and myeloid sarcoma.