Anti-CD19 CAR T-cells have been shown to induce deep B-cell depletion and sustained drug-free remission in patients with systemic lupus erythematosus (SLE), idiopathic inflammatory myositis (IIM), and systemic sclerosis (SSc) [14,15,16,17,18,19,24,29]. Here, CD19 is linked to acquired idiopathic inflammatory myopathy.