Thus, expression of V. cholerae respiratory enzymes such as nitrate (Nap), TMAO (Tor), and fumarate reductases (Frd) were also induced during infection experiments in mice, and consistently, inactivation of Nap and Tor respiratory systems reduced V. cholerae fitness during intestinal colonization in mice (Table 2; Oh et al., 2014; Bueno et al., 2018). Here, RORC is linked to infection.