Though present in low numbers, dendritic cells (DCs) are recognized as major players in the control of cancer by adaptive immunity. The roles of cytotoxic CD8 + T-cells and Th1 helper CD4 + T-cells are well-documented in murine models of cancer and associated with a profound prognostic impact when infiltrating human tumors, but less information is known about how these T-cells gain access to the tumor or how they are primed to become tumor-specific. Here, we highlight recent findings that demonstrate a vital role of CD103 + DCs, which have been shown to be experts in cross-priming and the induction of anti-tumor immunity. We also focus on two different mediators that impair the function of tumor-associated DCs: prostaglandin E 2 and β-catenin. Both of these mediators seem to be important for the exclusion of T-cells in the tumor microenvironment and may represent key pathways to target in optimized treatment regimens against cancer.