A multidisciplinary research team has uncovered direct evidence that common respiratory viruses—such as influenza and SARS-CoV-2—can reactivate dormant metastatic breast cancer cells in the lungs. Using mouse models and supported by human data analyses, the study found that viral infection-induced inflammation awakens dormant cancer cells, promoting metastasis. Interleukin-6 (IL-6) and T cell immune responses were implicated in this process. These findings highlight a critical link between infectious diseases and cancer progression, with implications for managing cancer survivors during periods of viral outbreaks.