sentences:  The mechanism of action of a PARP1 inhibitor is to enhance the damage done by chemotherapy on the cancerous DNA by disallowing the reparative function of PARP1 in BRCA1/2 deficient individuals .PARP14 is another ADP-ribosylating enzyme that has been well-studied in regards to cancer therapy targets; it is a signal transducer and activator of STAT6 transcription-interacting protein, and was shown to be associated with the aggressiveness of B-cell lymphomas.Bacterial ADP-ribosylating exotoxins (bAREs) covalently transfer an ADP-Ribose moiety of NAD+ to target proteins of infected eukaryotes, to yield nicotinamide and a free hydrogen ion.