RBFOX3 and neurodegenerative disease: NeuN markers can facilitate the assessment of ganglion cell tumors and hamartomas, hypoxic–ischemic damage, neuronal migration disorders, neurodegenerative diseases, epilepsy, etc. However, a few neuronal cell types are devoid of staining because NeuN is not expressed in glial cells, oligodendrocytes, retinal photoreceptor cells, mitral cells of the olfactory bulbs, and cerebellar Purkinje cells [143].