Metastatic Breast Cancer: TIL it is Too Late.

Paired analysis of primary and metastatic triple-negative breast cancers shows that metastatic disease is an immunodepleted state. This understanding has important implications for targeting the immune microenvironment in breast cancer, placing a greater emphasis on earlier stage disease and shaping future treatment strategies in the metastatic setting.See related article by Hutchinson et al., p. 657.