CHI3L1 and infarction: Although we could not determine whether chronic stable atherosclerotic lesion or acute injured lesion by infarction contributed more to the difference in serum YKL-40 levels between LAA and SVO, we postulate that the differences in YKL-40 levels on D2 between the 2 subtypes was more attributable to acute ischemic neuronal injury or peri-infarction inflammation than to chronic stable atherosclerotic lesion due to the rapid elevation in median YKL-40 levels on D2 compared to D1 only in LAA type AIS.