AuthOr’s VIew AuthOr’s VIew

While the importance of cancer cell-intrinsic genetic alterations in oncogenesis is well established, the role of the tumor microenvironment in tumor progression is being increasingly recognized. In many types of cancer, the nature and abundance of the immune cells that infiltrate the pri-mary tumor is an independent predictor of patient survival. In most studies, primary tumor infiltration by CD8+, T H 1 or natural killer (NK) cells is associated with a favor-able disease outcome, while infiltration by regulatory T cells (Tregs), macrophages or myeloid-derived suppressor cells (MDSCs) correlated with accelerated tumor growth and metastatic disease. The transcriptomic analysis of neoplastic lesions has led to the identification and validation of gene signa-tures with prognostic and predictive values. Some of the most potent signatures derive from the tumor stroma or from tumor-infiltrating immune cells. Therefore, an attractive strategy to improve the survival of cancer patients would be to modify the tumor stroma and make it permissive for infiltration by antitumor immune cells. Such approaches could also potentiate the efficacy of anticancer vaccines, which are known to induce circulating effector Immunomodulation of the tumor microenvironment by Toll-like receptor-3 (TLR3) ligand