The present invention pertains to a novel BTB-POZ domain zinc finger protein, which is named herein RI.alpha.-associated zinc finger (RIAZ). The nucleic acid and corresponding protein products have been identified, as have numerous diagnostic and therapeutic utilities predicated on the observed role that the factors play as mediators of the progression of several cancers, and the host response to multiple stress. We have cloned and sequenced the full length cDNA of the gene expressing this protein. We demonstrate that in vitro synthesized RIAZ protein interacts with RI.alpha.. We hypothesize that the interaction of RI.alpha. with RIAZ may regulate apoptosis, cell growth and drug resistance. The factors of the invention are also believed to play a role in host chemosensitivity to cancer drugs, and the invention extends to the modulation of the factors to treat conditions reflective of abnormal levels thereof. Also, the factors may be included in diagnostic assays, including drug discovery assays, to identify patient condition and progression during cancer therapy, as well as to identify possible new anticancer agents.