PIF1 and neoplasm: 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).