IL33 and infection: The immunostaining of liver tissues revealed that IL-33 was initially expressed only in the sinusoidal and vascular endothelial cells in the liver of control WT mice (Figure 1(c), brown staining in PBS condition) and induced in the nuclei of hepatocytes during L2-MHV3 infection (48 h and 72 h PI) (Figure 1(c), arrow).