Interestingly, as T cells migrated into close proximity of tumor cells, the density of detectable ARC (Fig. 6a; visualized as white in the phase and red in the IF) increased significantly, suggesting that the ARC is able to coat PD-L1 on the tumor cell surface, and then functionally cluster OX40 receptors on the T cell at the physical interface between an interacting T cell and tumor cell. Here, CD274 is linked to neoplasm.