By contrast, upon infection of mice with the WNVKUN35911 strain, the percentage of cleaved caspase 3-positive cells was low (below 50%) in almost all areas of the brain (Figure 1E and Figure 2F), suggesting that a caspase 3-independent mechanism was mainly responsible for WNVKUN35911-induced apoptosis. Here, CASP3 is linked to infection.