Several cases of RA with coexisting myasthenia gravis, SSc, Sjogren’s syndrome, and DLBCL demonstrated that CD19-directed CAR T-cell therapy not only achieved stable clinical remission but also led to seroconversion of anticitrullinated protein antibody (ACPA), indicating the eradication of ACPA-specific plasma cells (126–129). This evidence concerns the gene CD19 and diffuse large B-cell lymphoma.