Despite the proved potential of both PET and MRI for the microglial imaging, very few studies have integrated both the modalities in humans and, generally, the majority use MRI to simply colocalize TSPO-uptake with multiple sclerosis plaques identified by MRI (Colasanti et al., 2014; Kang et al., 2018; Unterrainer et al., 2018; Kaunzner et al., 2019). This evidence concerns the gene TSPO and multiple sclerosis.