TLR2 and bacterial infectious disease: Because the expression of DDX5 decreased following treatment with TLR2/4 agonists in both MEFs and mouse macrophages, we hypothesized that post-translational modifications, such as phosphorylation, SUMOylation, or ubiquitination could be involved in downregulating DDX5 upon bacterial infection (Clark et al, 2008; Li et al, 2021; Zheng et al, 2021).