1. Supplementary Figure 1: Correlation analysis of DKC1 mRNA and dyskerin protein quantity in neuroblastoma cell lines

2. B A Supplementary Figure 2: Correlation analysis of telomerase activity gene expression in neuroblastoma cells

3. Supplementary Figure 3: Correlation analysis of TERT and MYC gene expression in neuroblastoma tumor samples

4. Supplementary Figure 4: High DKC1 expression is a marker of poor prognosis in neuroblastoma OS C DKC1 MedianDKC1 Upper Decile B D OS Overall survival probability Days from diagnosis Overall survival probability Days from diagnosis Low DKC1 High DKC1 Low DKC1 High DKC1 P < 0.0001 B EFS DKC1 MedianDKC1 Upper Decile A Event-free survival probability Days from diagnosis Event-free survival probability Days from diagnosis Low DKC1 High DKC1 Low DKC1 High DKC1 EFS P < 0.0001

5. Supplementary Figure 5: Analysis of TERT expression in neuroblastoma tumor samples Kocak (n=477) Days from diagnosis High TERT Low TERT P < 0.0001 Days from diagnosis Event-free survival probability High TERT Low TERT P < 0.0001 EFSOS Overall survival probability BA

6. A B Supplementary Figure 7: Upregulation of p21 cip1 in NB69, but not SK-N-BE(2) cells following down regulation of dyskerin NB69 SK-N-BE(2)

7. Sub G1/0 Events FL-2 (PI) NB69 ScD2 Events D3 FL-2 (PI) A SK-N-BE(2) Events ScD2D3 FL-2 (PI) C Sub G1/0 Events FL-2 (PI) SK-N-BE(2) F D NB69 B E SK-N-BE(2) Supplementary Figure 8: Cell cycle and viability following downregulation of dyskerin ScD2D3 D2 D3 NB69 Sc