E2F1 and cancer: The known transcriptional activities of PARP1 which are involved in promotion of cancer include a) interactions with and activation of promoters of key pluripotency genes protecting these genes from epigenetic repression [14]; b) binding to a transcription factor E2F1 and functioning as a strong activator of E2F1 [15]; and c) modulation of chromatin on the c-myc promoter leading to activation of c-myc gene [16].