Although IRF5 is primarily known as a transcriptional immune regulator [2,4,6,11,13,15], our lab and others have shown that it is also a critical regulator of DNA damage-induced apoptosis [8,19,21] and expression of IRF5 is lost in a variety of cancers [16,19,23-27] supporting an important tumor suppressor role for IRF5. The gene discussed is IRF5; the disease is cancer.