What Kind of Stroke Is It?

The search for protein biomarkers in peripheral blood to aid in the diagnosis of stroke and the prediction of prognosis after stroke and risk of future stroke is an active area of investigation. Although some markers, such as S100b and neuron-specific enolase, have been shown to have prognostic value in ischemic stroke (1, 2), no biochemicalmarkers have proven to be really useful in routine clinical practice. In this issue of Clin-ical Chemistry, Nybo and associates present similarly discouraging data for osteoprotegerin as a potential stroke biomarker (3). Why are we continuing to see lack of demonstrated clinical utility in studies for stroke biomarkers? Should the search for biomarkers for stroke be abandoned? Some answers may lie in the deceptively simpl