Effector proteins function to alter host cell physiology and promote bacterial survival in host tissues. Does not appear to be required for the formation or the maintenance of either Salmonella-containing vacuole (SCV) or the Salmonella-induced filaments (Sifs). Not required for intracellular replication in phagocytic cells. Secreted via type III secretion system 2 (SPI-2 TTSS), and delivered into the host cell. Concentrates in detergent-resistant microdomains (DRMs) that are present on the membranes of Salmonella-containing vacuole (SCV) and Salmonella-induced filaments (Sifs). Expression is regulated by the two-component regulatory system SsrA/SsrB. Induced after bacterial entry into host cell.