The significant functional neurological improvement in five patients treated with anti-BCMA CAR-T cells (follow-up of 9 months) was not obtained for treatment of two patients with progressive MS following anti-CD19 CAR-T cells, with the longest follow-up of 100 days.1,2 It was discussed that CD19-targeting CAR-T cells can penetrate the CNS, but are hardly capable of eliminating long-lived plasma cells. The gene discussed is CD19; the disease is myeloid sarcoma.