RTN4R and neoplasm: To overcome these issues, several strategies such as the use of antibodies against vascular endothelium growth factor (VEGF) and its receptors [41,45,46], irradiation [47], or cytokine targeting (e.g., tumor necrosis factor-α (TNFα)) with tumor vasculature NGR (Asn-Gly-Arg) and RGR (Arg-Gly-Arg) homing peptides [41,48], have focused on the normalization of blood vessels in the tumor to facilitate immune cell infiltration.