The majority of neuroblastoma and medulloblastoma cell lines transfected with PPM1D shRNA were non-viable compared to scrambled controls (data not shown), whereas cells that were viable after transfection showed reduced proliferation and increased H2AX phosphorylation, suggesting an effect on cell viability and genomic integrity (Figure 3A and Figure S2). The gene discussed is H2AX; the disease is medulloblastoma.