B2M and Stroke: Figure 1 shows the serum levels of biomarkers in different stroke risk groups. Elevated biomarker levels were found in the high-risk group (2.53 ± 0.71 mg/L for B2M, 0.62 ± 0.14 mg/L for cystatin C, 0.21 ± 0.13 mg/L for LCN-2; p < .001).