RNAseq from samples serially harvested across tumor development, by sorting EdU-pulsed cells from the adult, postmitotic cerebellum at P35, P50, and P75, revealed that Pif1 upregulation occurred as early as P35, which coincided with early tumor development (Fig. 4A and SI Appendix, Fig. S1D). Here, PIF1 is linked to neoplasm.