Upon infection, L.p. secretes ∼300 effector proteins through a type IV secretion system, some of which enable recruitment of ER/ERGIC proteins CNX, Sec22b, Rab1, ERGIC-53, and Arf1 to the LCV (Derré and Isberg, 2004; Kagan and Roy, 2002; Kagan et al., 2004), which are needed for its replication. The gene discussed is ARF1; the disease is infection.