NOD1 mRNA levels are increased in fibroblasts and macrophages after stimulation with L. monocytogenes or incubation with TLR ligands. The levels of NOD1 mRNA transcripts in WT BMM (A, C, and D) or fibroblasts (B) infected with L. monocytogenes (A and B) or stimulated with CpG (C and D), poly(I-C) (C), LPS (C), Pam3 (D), or MALP-2 (D) were determined by real-time RT-PCR. The mean increases in the level of NOD1 mRNA for duplicate wells for each condition compared to the level for unstimulated wells are shown. SEM, standard error of the mean.