After classifying patients according to the TOAST criteria, the highest quartiles of IL-6 and YKL-40 were associated with increased risk of recurrent stroke only in the patients with large-artery atherosclerosis (IL-6: HR, 1.66; 95% CI 1.21–2.29; P = 0.002; YKL-40: HR, 1.81; 95% CI 1.32–2.48; P = 0.0002) and small-vessel occlusion (IL-6: HR 1.67; 95% CI 1.06–2.64; P = 0.03; YKL-40: HR 1.84; 95% CI 1.17–2.88; P = 0.008) subtypes (Additional file 1: Table S11). Here, IL6 is linked to stroke disorder.