Secreted protein that plays a role in the inhibition of host immune system. Targets myeloid cells such as monocytes or granulocytes through binding with sialyllactosamine-containing glycoproteins. Prevents initial rolling of neutrophils toward the site of infection by interacting with host SELPLG. Disrupts neutrophil motility by induction of cell adhesion via interacting with glycans but independently of SELPLG. Homodimer (via its C-terminal domain). Interacts with host FCAR and SELPLG (via sialyl Lewis X). The C-terminal domain contains a V-shape binding site for sialyl Lewis X. Belongs to the staphylococcal/streptococcal toxin family.