SELL and neoplasm: The infiltration of neutrophils into the tumor sites is thought to be mediated by the intercellular adhesion molecule of ICAM-1 [29,30] and L-selectin [25,31] expressed on the tumor vascular endothelium, as well as ICAM-1 ligands (CD11b/CD18 and CD11c/CD18) that are upregulated on neutrophils following Photofrin-PDT [30].