PK 11195 (RP 52028) is a translocator protein (TSPO) ligand, a potent and selective antagonist of peripheral benzodiazepine receptorwith high affinity Ki of 3.1 nM in cerebellum and 4.1 nM in spinal cord. It is also an antagonist of human constitutive androstane receptor (hCAR), and human pregnane X receptor (PXR). It displaces [3H] RO5-4864 from its binding sites across organs and also targets Leishmania in chemotherapy.