Table 2. The node marker-panel is a collection of gene-pair classifiers from the nodes of the diagnostic hierarchy.

Node #a	Node classesb	Gene i c	Gene j c	k d
2	EPN GBM MDL MNG OLG PA	PRPF40A	PURA	1
3	normal	PURA	PRPF40A	1
4	EPN GBM MDL OLG PA	NRCAM	ISLR	1
		IDH2	GMDS
5	MNG	ISLR	NRCAM	1
6	EPN GBM OLG PA	SALL1	PAFAH1B3	2
		SRI	NBEA
		DDR1 e	TIA1
		DDR1 e	MAB21L1
		ITPKB	PDS5B
7	MDL	PAFAH1B3	SALL1	4
		NBEA	SRI
		TIA1	DDR1 e
		MAB21L1	DDR1 e
		PDS5B	ITPKB
8	EPN	NUP62CL	ZNF280A	2
		GALNS	WAS
		CELSR1	OR10H3
		TLE4	OLIG2
9	GBM OLG PA	ZNF280A	NUP62CL	1
10	GBM OLG	DDX27	KCNMA1	1
		COX7A2	GNPTAB
11	PA	KCNMA1	DDX27	3
		GNPTAB	NDUFS2
		APOD	PPIA
		CD59	SNRPB2
		SEMA3E	ADAMTS3
		CD59	HINT1
		BAMBI	CIAPIN1
12	GBM	FLNA	TNKS2	1
		ITGB3BP	RB1CC1
		DDX27	TRIM8
13	OLG	LARP5	ANXA1	1

^aNode # corresponds to numerical labels in the diagnostic hierarchy shown in Figure 1.

^bDisease abbreviation (name): EPN (Ependymoma), GBM (Glioblastoma Multiforme), MDL (Medulloblastoma), MNG (Meningioma), OLG (Oligodendroglioma), PA (Pilocytic astrocytoma), and normal (Normal brain).

^cGene i and gene j are the genes expressed higher and lower, respectively, within each gene-pair classification decision rule. Specifically, the statement of “Gene i is expressed higher than Gene j” being true contributes to the expression profile being classified as the phenotype(s) of the node. Gene names, chromosome loci, and Affymetrix microarray platform probe IDs of the classifier genes can be found in Table S1.

^dThe minimum number of gene-pair classifiers whose decision rule outcomes for an expression profile are required to be ‘true ( = 1)’ for the profile to be classified as the phenotype(s) of the node.

^eGenes that share same symbol/name, but correspond to different Affymetrix probe IDs.