Fig. 4. Relationship between two interrelated biomarkers in different overlapping populations, normal subjects (gray circles), and pathological subjects (open triangles). The concentrations of biomarkers A and B both increase until a point where they start to plateau (change in curvature, dashed vertical line), which is considered the functional reference limit.

Ann Lab Med 2023;43:408~417 https://doi.org/10.3343/alm.2023.43.5.408