Taken together, functional concepts involving NKCC1 and CFTR in fluid transport and edema formation (Figure 1A) in combination with data demonstrating differential regulation of NKCC1 and CFTR in lung injury that coincides with edema formation point toward a critical role for CFTR and NKCC1 in infection-induced pulmonary edema. This evidence concerns the gene SLC12A2 and infection.