Autologous tumor rejection in humans: trimming the myths

There is overwhelming evidence that the human immune system can keep in check the growth of autologous tumors. Yet, this phenomenon is rare and most often tumors survive striking a balance with the host's immune system. The well-documented coexistence of immune cells that can recognize cancer and their targets within the same host is reminiscent of chronic allograft rejection well-controlled by immune suppression or of a lingering tissue-specific autoimmune reaction. In this review, we argue that autologous tumor rejection represents a distinct form of tissue-specific rejection similar to acute allograft rejection or to flares of autoimmunity. Here we discuss similarities within the biology of these phenomena that may converge into a common immunological constant of rejection. The purpose is to simplify the basis of immune rejection to its bare bones critically dissecting the significance of those components proposed by experimental models as harbingers of this final outcome.