Xu et al. (2013) demonstrated that elevated levels of c-di-GMP increases UPP and BC production, while VisN and VisR, activators of flagellar motility (Sourjik et al., 2000), act to inhibit UPP and BC biosynthesis by repressing the DGCs DcgA, DcgB, and CelR (Figure 5). They also showed that mutations in the PDE, Atu3495, results in increased levels of c-di-GMP, UPP and BC while reducing motility. Additionally, over-expression of the DGC genes, celR and atu1060, increases BC production, while deletion of celR, but not atu1060, decreases BC production (Michael Barnhart et al., 2013). Here, ALDH7A1 is linked to breast cancer.