PARP3 and cancer: Poly(ADP-ribose) polymerase 3 (Parp3), the third member of the DNA damage-dependent PARP family subgroup, is well recognized for its biochemical and cellular roles in the repair of double-strand breaks by the classical non-homologous end-joining (c-NHEJ) route, in the control of telomere segregation for faithful mitosis and in cancer aggressiveness.1