Tissue-resident memory T cells at the center of immunity to solid tumors

Immune responses in tissues are constrained by the physiological properties of the tissue involved. Tissue-resident memory T cells (T RM cells) are a recently discovered lineage of T cells specialized for life and function within tissues. Emerging evidence has shown that T RM cells have a special role in the control of solid tumors. A high frequency of T RM cells in tumors correlates with favorable disease progression in patients with cancer, and studies of mice have shown that T RM cells are necessary for optimal immunological control of solid tumors. Here we describe what defines T RM cells as a separate lineage and how these cells are generated. Furthermore, we discuss the properties that allow T RM cells to operate in normal and transformed tissues, as well as implications for the treatment of patients with cancer. Tissue-resident memory T cells provide immunological protection in peripheral tissues. Amsen et al . discuss the role of these cells in the context of anti-tumor immunity.