Impact of norovirus infection on TLR expression in mice. The ileum with PPs (a) and the MLNs (b) from BALB/c mice (6 weeks old, n = 9–10 per group) infected with MNV-1 as in Fig. 5 were retrieved 2 days after viral infection and expression of TLR mRNA was quantified as described in Fig. 2f. Data are represented as mean ± SD. *P < 0.05; **P < 0.01; ***P < 0.001; n.s., not significant; by two-tailed unpaired Student’s t-test.