TSPO and post-traumatic stress disorder: Interestingly, our group was the first to show that oral administration of certain TSPO ligands, including AC-5216 and YL-IPA08, enhanced synthesis of neurosteroids (such as Allo) in the brain and exerted anti-PTSD-like effect in some PTSD animal models with a favorable side effect (Qiu et al., 2013; Zhang et al., 2014a, 2016).