These findings are supported by the increased expression of GFAP and S100β, two established markers for glia cells, associated with a reduced positivity for HuC/D, a neuronal marker, in the small intestine of mice subjected to CPT-11-induced mucositis (jejunum and ileum data not shown), suggesting glial activation and neuronal loss in the ENS. This evidence concerns the gene GFAP and mucositis.