We performed flow evaluations using antibodies specific to human CD3, CD4, CD8, CD19, CD27, CD45, CD45RA, CD62L, CCR7, B7-H3, PD-1, PD-L1, and TIM3 and murine CD3, CD4, CD8, CD11b, CD11c, PD-1, and Ly-6G (from BD Biosciences and BioLegend) conjugated with BV421, BV510, BV605, BV711, fluorescein isothiocyanate (FITC), AF488, peridinin chlorophyll protein (PerCP)–cy5.5, phycoerythrin (PE), PE-cy7, allophycocyanin (APC), and APC-cy7 fluorochromes. Expression of human B7-H3 by tumor cell lines was assessed with the 376.96 monoclonal antibody and confirmed with the commercial B7-H3 antibody clone 7-517 (BD Biosciences) (16 (link)). Expression of B7-H3.CAR was evaluated using the fusion protein 2Ig-B7-H3-GFP. Samples were acquired with BD FACSCanto II or BD LSRFortessa using the BD FACSDiva software (BD Biosciences). Quantification and characterization of T cells within the tumor were obtained by generating single-cell suspension of the tissues using the Human Tumor Dissociation Kit (Miltenyi Biotec) as per the manufacturer’s instructions. For each sample, a minimum of 10,000 events was acquired, and data were analyzed using FlowJo version 10.