With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Rey Mysterio won the nineteenth annual Royal Rumble in 2006.
text_B: The zona incerta is a horizontally elongated region of gray matter in the subthalamus below the thalamus .. gray matter. gray matter. subthalamus. subthalamus. thalamus. thalamus. Its connections project extensively over the brain from the cerebral cortex down into the spinal cord .. brain. brain. cerebral cortex. cerebral cortex. spinal cord. spinal cord. Its function is unknown , though several potential functions related to `` limbic -- motor integration '' have been proposed , such as controlling visceral activity and pain ; gating sensory input and synchronizing cortical and subcortical brain rhythms .. brain. brain. Its dysfunction may play a role in central pain syndrome .. central pain syndrome. central pain syndrome. It has also been identified as a promising deep brain stimulation therapy target for treating Parkinson 's disease .. brain. brain. deep brain stimulation. deep brain stimulation. Its existence was first described by Auguste Forel in 1877 as a `` region of which nothing certain can be said '' .. Auguste Forel. Auguste Forel. A hundred and thirty years later in 2007 , Nadia Urbain and Martin Deschenes of Universite Laval noted that the `` zona incerta is among the least studied regions of the brain ; its name does not even appear in the index of many textbooks . ''. brain. brain. Universite Laval. Universite Laval
not_related.