Comparison of abundantly expressed (more than 3 ESTs) genes in ON, compared with abundantly expressed genes in other libraries representing white matter, astrocytes and macrophages. A) CC: human corpus callosum (dbEST:16383). MS: Multiple sclerosis lesions (dbEST: 390). DR: Human dorsal root ganglion (dbEST:5655). B) MA: Human purified macrophages (dbEST:16419). AS: human purified astrocytes (dbEST:18304).