PARP1 and cancer: Isabelle Chemin (Cancer Research Center of Lyon, INSERM, CNRS, Lyon, France) presented Update on Hepatocellular Carcinoma (HHC) Breakthroughs, do carcinomas have an Achilles Heal. Poly (ADP-ribose) polymerase (PARP) is a family of proteins involved in a number of cellular processes such as DNA repair, genomic stability, and programmed cell death.