E2F1 and cancer: Among the E2F family members, E2F4 and E2F1 have the highest combined expression in three different human PDAC patient-derived organoids (HCM-BROD-0124-C25; HCM-BROD-0009-C25; HCM-CSHL-0073-C25) based on RNA-seq data available via the Human Cancer Models Initiative (Supplementary Fig. 4e) while in CSCs of PDAC cell lines E2F4 is similarly the most abundant (Supplementary Fig. 4f ).