MAG and neoplasm: Within the grey matter, tumour cells are frequently found immediately adjacent to neuronal cell bodies, where they are often referred to as satellite cells (satellite cells within the sensory ganglia of the peripheral nervous system are present in large numbers but represent Schwann cells) (Figure 1A) [1,2,6,24,25,26,27]; although immunohistochemical stains for myelin-associated glycoprotein (MAG) and for myelin basic protein (MBP) have been used to reveal oligodendroglia cells, with varying success they did not reveal reliable or reproducible results.