Gone but not forgotten: CAR-NK cells leave a lasting mark on autoimmunity.

In this phase 1 open-label trial, Zeng et al.1 show that umbilical cord blood-derived CD19 CAR NK-cell therapy is safe and effectively depletes autoreactive B cells in refractory systemic lupus erythematosus (SLE). Despite only transient CAR NK-cell persistence, patients experienced sustained clinical improvement and reconstitution of a predominantly naive B cell compartment, suggesting immune resetting rather than temporary immunosuppression.