ITGA4 and Sepsis: Analysis of neutrophil surface marker expression revealed that CD11c, which is expressed on neutrophils during inflammation and sepsis, CD49d, the integrin α subunit of VLA-4, which is involved in migration of leukocytes, and CXCR2 the receptor for CXCL1, were enhanced on Siglec-F+ compared with Siglec-F− neutrophils (Fig. 10b).