TSPO and REM sleep behavior disorder: Positron emission tomography (PET scan) studies using the radiotracer [11C](R)-PK11195, which labels “translocator protein 18 kDa (TSPO),” mainly expressed by microglia (Banati, 2002) and considered to modulate their inflammatory activity and phagocytosis (Karlstetter et al., 2014), revealed an increased binding of the radiotracer in the substantia nigra of patients with idiopathic REM sleep behavior disorder, thus identifying microglial “activation” as a potential therapeutic target for halting or delaying the neurodegenerative process.