CD19 and systemic lupus erythematosus: The therapeutic potential of CAR-T therapy in SLE was first demonstrated in a landmark study by Mougiakakos et al., who reported the successful use of anti-CD19 CAR-T cells to treat a patient with refractory SLE and lupus nephritis, achieving serological remission including seroconversion of anti-dsDNA antibodies in the absence of significant adverse events, thereby establishing a foundational milestone for the field (3).