PARP1 and neoplasm: Early reports claimed that the PARP inhibitor 3-aminobenzamide was a radio-sensitizer only in rodent cells [21] however more recently ANI (1000-fold more potent at inhibiting PARP activity compared with 3-aminobenzamide (3-ABA)) has been found to be radiation sensitizer to both rodent and human tumor cells [9,15,22].