At the left, an H&E stain shows a rounded pink cytoplasmic Lewy body in a neuron of the cerebral cortex from a patient with diffuse Lewy body disease, which can be a cause for dementia. Lewy bodies can also be seen in substantia nigra with Parkinson disease. An immunohistochemical stain for ubiquitin, seen at the right, helps demonstrate the Lewy bodies more readily by the collection of intense brown reaction product within them.