VCAM1 and neoplasm: RT can upregulate expression of adhesion molecules, such as VCAM-1, E-selectin, and ICAM-1, by vascular endothelial cells within the tumor and induce expression of T cell chemokines that promote T cell adhesion and extravasation into the tumor microenvironment (Handschel et al., 1999; Lugade et al., 2008).