For this reason, initial studies of the Rcs phosphorelay system focused mainly on the enteropathogenic Yersinia to reveal an important role in bacterial survival when grown under a variety of environment stresses (Hinchliffe et al., 2008) or during the initial stages of gastrointestinal colonization in a murine model of infection (Venecia and Young, 2005; Figure 4C). Here, ARPP21 is linked to infection.