A small molecule iodobenzamide with potential cytotoxic and antineoplastic activities. Although the mechanism of action is unknown, iniparib appears to be cytotoxic in cells with DNA alterations or DNA damage, like that found in tumor cells with mutations in the ataxia telangiectasia mutated (ATM) gene. ATM encodes a serine/threonine protein kinase and mutations of the gene are associated with ataxia telangiectasia and contribute to certain cancers such as T-cell acute lymphoblastic leukemia, B-cell chronic lymphocytic leukemia and B-cell non-Hodgkin lymphomas.