NSG mouse xenograft models with grafted human PBMCs facilitate in vivo assessments of anti-tumor immunity of BP-αCD3-αEGFR-ARC Exos targeting human cancer and T cells, but prevent evaluations of host immune responses and feasibility of repeated administration of BP-αCD3-αEGFR-ARC Exos, which are important for clinical translation. Here, ARC is linked to cancer.