Remarkably, TLRs are expressed not only in immune cells but also in tumor cells, where they can both inhibit and promote malignancy [117]. Copious studies in humans and mice underline the importance of endogenous type I IFN, produced by both immune and tumor cells, in the control of tumor growth and in the response to anti-tumor therapies [118-120]. Seneff et al. [23] extensively discuss the complexity and the role of type I IFNs, particularly IFN-α, in cancer surveillance and cancer suppression. The gene discussed is IFNA1; the disease is cancer.