E2F1 and neoplasm: This observation is in contrast to previous studies which have shown that E2F1 is essential for inducing apoptosis in response to genotoxic treatment in early tumor cells,54 however elevated E2F1 expression results in resistance to apoptosis in late stage tumor cells (reviewed in Ref.[55]) which suggests a dual role of this gene in regulating cell viability/apoptosis of PDAC cells.