TLR4 and bacterial urinary tract infection: Consistent with an essential role for TLR4‐signaling induction of NOS2 expression during UPEC‐UTI, NOS2 mRNA abundance was >10 fold higher in normal HeN compared to Tlr4‐deficient HeJ mice (Figure 1b; mean ± SE: N HeN = 1.2 ± 0.34 vs. N HeJ 0.07 ± 0.03).