CD19 and systemic lupus erythematosus: Notably, the regulatory approval of CAR-T cell therapies that target CD19, a marker stated on the surface of B cells, has catalyzed advancements in applying CAR technology beyond oncology, fostering pioneering translational research in areas such as autoimmune disorders, with systemic lupus erythematosus (SLE) being a prime example [4–6], myasthenia gravis [7], rheumatoid arthritis [8], and multiple sclerosis [9], and has demonstrated the durable efficacy of high specificity for the removal of B cells and the preservation of remission.