GPR139 and Parkinson disease: The GPR139 agonist JNJ‐63533054 induced a dose‐dependent reduction in locomotor activity in rats.1 Bayer Andersen et al11 have recently reported that the GPR139 agonist TC‐O 9311 protected primary mesencephalic dopamine neurons against 1‐methyl‐4‐phenylpyridinium (MPP+)‐mediated degeneration, indicating a potential role of GPR139 in neuroprotection and Parkinson's disease.11 Another GPR139 agonist, 4‐oxo‐3,4‐dihydro‐1,2,3‐benzotriazine, has been reported to improve social withdrawal.12