Table 1B:

Patient and Tumor Characteristics

Feature	Discovery cohort (n = 32), %	Validation cohort (n = 21a), %	Healthy Controls (n = 34), %
Median age at diagnosis	36.0 months	48.0 months	18.5 months
Age at diagnosis
≤ 18 mo	25	14.3	50
18 mo - 5 yr	43.8	38.1	26.5
> 5 yr	31.2	47.6	23.5
Sex
Male	50	52.4	50
Female	50	47.6	50
Race
White	81.2	76.2	38.2
Black	6.3	23.8	44.1
Asian	3.1	0	5.9
Unknown	9.4	0	11.8
Ethnicity
Non-Hispanic	78.1	95.2	85.3
Hispanic	12.5	4.8	2.9
Unknown	9.4	0	11.8
Sample collection time
Diagnosis	28.1	4.8
During Therapy	21.9	38.1
End or Off Therapy	25	19
Relapse or progression	25	38.1
INSS Stage
4	71.9	61.9
4S	3.1	0
3	12.5	33.3
2	9.4	4.8
1	3.1	0
Risk
High	84.3	95.2
Intermediate	6.3	4.8
Low	9.4	0
MYCN
Non-Amplified	71.9	66.7
Gain	3.1	0
Amplified	18.7	19
Unknown	6.3	14.3

Abbreviations: INSS, International Neuroblastoma Staging System.

^a7 of these patients had samples in the Discovery cohort.