A continuous decrease in IgM, kappa light chains and kappa-to-lambda light chain difference was observed in the patient from day + 30 on, resulting in a deep hematological response six months after treatment.In summary, we present a novel case of CAR T cell treatment with third generation CD19 directed infusion for AL amyloidosis with an underlying secretory active B cell lymphoma, showing that this is an effective treatment modality and can be applied to patients with subsequent AL amyloidosis. The gene discussed is CD40LG; the disease is AL amyloidosis.