Chimeric antigen receptor (CAR)-T cell therapy is a novel treatment with definite curative effects for some hematological cancers.14–16 B cell maturation antigen (BCMA)-based CAR-T cells have significantly improved outcomes in patients with refractory/relapsed (R/R) multiple myeloma (MM), with objective response rates (ORRs) of more than 80% and complete remission (CR) rates of up to 60%.17–20 To avoid viral reactivation or fulminant hepatitis, clinical trials of CAR-T cell therapy have generally excluded patients with aggressive MM coinfected with HBV. This evidence concerns the gene TNFRSF17 and AL amyloidosis.