The latter is in contrast to our previous study conducted in hSOD1G93A rats, where CD88 was expressed primarily on proliferating astrocytes [11], but is in support of other studies that show CD88 on microglia in other neurodegenerative diseases [36,54] The differential expression of CD88 on these proliferating glial cells between hSOD1G93A rat and mouse models may suggest a differential role for CD88 in these two species. This evidence concerns the gene C5AR1 and neurodegenerative disease.