According to the recent report, three out of four enrolled patients with relapsed B cell or T cell malignancies eventually achieved CR; however, one patient with refractory double-hit high-grade B cell lymphoma (HGBCL), who relapsed after CD19 CAR-T, experienced disease progression post CD37 CAR-T administration with a CD19-negative and CD37-negative phenotype. Here, CD37 is linked to B-cell non-Hodgkin lymphoma.