Despite limited evidence on the failure of response due to BCMA escape among trials with Si-CAR T-cell therapy targeting BCMA, the combination of BCMA CAR and a second CAR is still being explored in MM [11,12], most of which adopt cocktail/sequential infusion of BCMA Si-CAR T cells and other Si-CAR T cells. This evidence concerns the gene TNFRSF17 and Miyoshi myopathy.