Preclinical studies have demonstrated that DMXAA efficacy in tumor models is the result of stimulation of TNF‐α generation which leads to tumor hemorrhagic necrosis.170 TNF‐α was shown to be able to potentiate the antitumor responses of PDT.171 Bellnier et al. first demonstrated that DMXAA can selectively enhance Photofrin‐based PDT in RIF‐1 tumor bearing mice.172 The enhanced PDT effect appeared to be dependent on TNF‐α induction, because neutralizing antibodies to TNF‐α reduced the antitumor efficacy to control levels. The gene discussed is TNF; the disease is neoplasm.