For generations, autoimmune disease has meant a lifelong negotiation with one's own immune system—managed but never resolved. Now, researchers have moved a single-dose intravenous therapy into early human trials, with preliminary findings suggesting it may be possible to retrain the immune system rather than merely suppress it. The distinction is profound: not a ceiling placed over a misfiring system, but a recalibration toward self-tolerance. It is too soon to call it a turning point, but it is the kind of early signal that quietly reshapes what medicine believes is possible.