Table 1. Validation set characteristics, based on data from discovery stage in this study, in addition to data from other gene expression profiling studies.

Entrez GeneID	Gene Symbol	Gene name	Chromosomal location	Fold change	FDR ♯	Supporting evidence from other studies	Function
539	ATP5O	ATP synthase, H+ transporting, mitochondrial F1 complex, O subunit	21q22.1-q22.2	2.29	8.20E-04	[4,9,10]	energy metabolism
6651	SON	SON DNA binding protein	21q22.11	2.51	4.32E-02	[4,7,9]	regulator of cell-cycle
6647	SOD1	superoxide dismutase 1, soluble	21q22.11	2.29	2.52E-05	[4,7,9,10,20]	involved in ROS metabolism
6453	ITSN1	intersectin 1 (SH3 domain protein)	21q22.1-q22.2	2.11	1.79E-02	[3,7,10]	actin assembly and trafficking
6612	SUMO3	SMT3 suppressor of mif two 3 homolog 3	21q22.11	2.53	4.33E-03	[3,4,9]	involved in ROS metabolism
10950	BTG3	BTG family, member 3	21q21.2	2.14	4.51E-03	[3,4,7,9]	role in neurogenesis
1827	RCAN1	regulator of calcineurin 1	21q22.12	2.33	4.58E-02	[3,7,9,10]	role in neurogenesis
10600	USP16	ubiquitin specific peptidase 16	21q22.11	3.24	4.78E-03	[4,7,9]	involved in ROS metabolism
3914	LAMB3	laminin, beta 3	1q32	0.16	5.79E-03	[7]*	laminin is a basement membrane protein

^♯FDR – stands for “false discovery rate”, proportion of anticipated false discoveries, according to Benjamini-Hochberg method of adjusting for multiple testing

^*Although LAMB3 was not identified in other studies, we incorporated it into our biomarker set, due to its marked and highly significant down-regulation in TS21 samples. Additionally, its down-regulation was not directly reported in [7], but it could nevertheless be detected in the same processed dataset in the Gene Expression Atlas (http://www.ebi.ac.uk/gxa/)