Identified candidate Down Syndrome (DS) biomarkers.

Potential for DS screening is indicated as follows: In use, currently widely used in 1st or 2nd trimester DS screening (in bold); Biomarker, studies showed overall significant concentrations; Examined, examined as biomarker but not significant or inconclusive overall results; Indications, found in high-throughput study but awaiting further study. References on the corresponding literature are given in the Discussion.