ITGA4 and neoplasm: Based on a recent study by Calzascia et al. demonstrating that up-regulation of VLA-4 expression on Ag-specific CTLs confers efficient CNS-tumor tropism [19], we evaluated expression of CD49d (Integrin α4 chain), a subunit for the VLA-4, on BILs (Fig. 4A) and SPCs (Fig. 4B) obtained from mice receiving OVA-vaccines and/or i.m. poly-ICLC administrations.