We aimed to identify the temporal dynamics of circulatory YKL-40 levels immediately following AIS, the relationship between YKL-40 levels and 3 key clinical parameters (infarct volume, stroke severity, and functional outcome), and the practical clinical application of YKL-40 in AIS by comparing it with C-reactive protein (CRP). The gene discussed is CHI3L1; the disease is androgen insensitivity syndrome.