Immunotherapy, particularly CAR T-cell therapy, has transformed cancer treatment, yet its long-term effects, especially on cognitive function, remain underexplored. A study using mouse models demonstrated that CAR T-cell therapy for both CNS and non-CNS cancers led to cognitive impairments and persistent CNS immune responses, characterized by microglial reactivity and elevated cytokine levels in the cerebrospinal fluid (ref: Geraghty doi.org/10.1016/j.cell.2025.03.041/). In the context of lymphoma, a novel CAR T-cell therapy, huCART19-IL18, showed promising results in patients with relapsed or refractory disease, achieving a complete or partial response in 81% of patients after three months, with a median duration of response of 9.6 months (ref: Svoboda doi.org/10.1056/NEJMoa2408771/). Furthermore, advancements in CAR T-cell therapy for solid tumors were highlighted by the use of a collagenase nanogel, which improved therapy outcomes in pancreatic cancer by enhancing T-cell infiltration (ref: Zhao doi.org/10.1038/s41565-025-01924-1/). These findings underscore the dual nature of CAR T-cell therapy, offering significant therapeutic potential while also posing risks of cognitive and immune system alterations.