FAS and infection: For example, Williams et al. showed that BDV He/80 infection increases neuronal apoptosis and selective degeneration of granule cell neurons of the dentate gyrus (DG) in neonatal Lewis rats; mechanistically, increased expression of the pro-apoptotic proteins Fas and caspase-1 was accompanied by a decreased expression of the anti-apoptotic protein Bcl-2 [8].