On 0.5 and 1.0 mg daily, laquinimod has shown favourable CNS kinetics and good tolerability in healthy volunteers and multiple sclerosis patients.9–11 To evaluate microglia activation in vivo, we employ 11C-PBR28, a second-generation PET radioligand that is highly specific for the translocator protein (TSPO).12–14. This evidence concerns the gene TSPO and multiple sclerosis.