Weng Y, Zeng T, Huang H, et al. - This study attempted to assess the association between systemic immune-inflammation index (SII) and severity of stroke as well as the 3-month outcome of acute ischemic stroke (AIS) patients. Researchers retrospectively enrolled a sum of 216 AIS patients receiving intravenous thrombolysis (IVT) and 875 healthy controls. They obtained blood samples within 24h after admission. They assessed the severity of stroke by the National Institute of Health stroke scale scores on admission and the poor 3-month functional outcome was defined as modified Rankin Scale > 2. It was shown that SII is associated with stroke severity at admission and can be a novel prognostic biomarker for AIS patients treated with IVT.