Surprisingly, Brd4 CKO mice are resistant to endotoxemia, but are more susceptible to intraperitoneal injection of group B Streptococcus-induced infection (Bao et al., 2017), which may result from the compromised innate immune response to clear bacteria in vivo. These findings not only demonstrate the importance of BRD4 in innate immunity against bacterial infection, but also highlight an unknown function of BRD4 in regulating the activity of bacterial LPS and non-LPS components. This evidence concerns the gene BRD4 and serum lipopolysaccharide activity.