CD37CAR T cells and CD19CAR T cells have comparable antitumor efficacy in vivo. NSG mice were engrafted with GFP/Luc⁺ BL-41 tumors or GFP/Luc⁺ U2932 tumors subcutaneously; 4 or 12 days, respectively, after tumor inoculation, mice were randomized and received intratumoral injections of mock T cells, CD19CAR T cells, or CD37CAR T cells (n = 5 for each group) every 3 days for 2 weeks. Tumor size was measured using a caliper. These experiments were reproduced twice. (A) BL-41 tumor growth curves after mock T cell, CD19CAR T cell, or CD37CAR T cell transfer. (B) Kaplan-Meier survival curves of mice shown in panel A. (C) Proportion of tumor-infiltrating lymphocytes, as detected by CD3 staining of tumor tissue single-cell suspension, using flow cytometry. The tumor samples were obtained at day 27. Data represent mean ± standard deviation of duplicates. (D) Percentage of tumor-infiltrating lymphocytes expressing PD-1 exhaustion marker. Data represent mean ± standard deviation of triplicates. (E) U2932 tumor growth curves after mock T cell, CD19CAR T cell, or CD37CAR T cell transfer. (F) Kaplan-Meier survival curves of mice shown in panel E. These experiments were reproduced twice. Survival curves were analyzed with a Mantel-Cox (log-rank) test. Data represent mean ± standard deviation. *P < .05, **P < .01.