Tumor microenvironment and lymphocyte infiltration.

There is ample evidence that the presence of tumor-infiltrating T lymphocytes is associated with a favorable prognostic in patients. These observations suggest that a limiting step to immune resistance and immunotherapy could be the capacity of tumor-specific T cells to reach tumor bed. In this article, we review some factors that may influence this infiltration, and in particular the nature of the vasculature, the expression of chemokines or tumor antigens and the presence of dendritic cells and CD4+ T lymphocytes.