The potential importance of G-quadruplex resolution in the BRCA2-deficient medulloblastoma was further highlighted when we assessed gene expression changes in tumor compared to age-matched normal cerebellum and identified that the 5’-3’ DNA helicase PIF1, which has ability to bind to G4s (42) and promotes processivity through G4s (43) was one of the most upregulated genes in tumors (Fig. 4A). The gene discussed is PIF1; the disease is medulloblastoma.