New data suggested that naïve CD4+ T cells can predict success in CAR T-cell therapy for large B-cell lymphoma. The report focused on why real-world outcomes vary widely despite the platform’s established efficacy, pointing to immune-cell composition as a potential determinant of response. The study’s core message is that baseline immunophenotyping may improve patient stratification by identifying those with immune profiles most likely to support durable CAR T activity. If validated in prospective datasets, the marker could inform manufacturing prioritization and pre-treatment selection. For developers of next-generation CAR T and supportive regimens, the results add to the growing shift from one-size-fits-all protocols toward immune-informed treatment planning.