Scientists have demonstrated that common respiratory viral infections, including SARS-CoV-2 and influenza, can awaken dormant breast cancer cells in the lungs, leading to increased metastasis. Using mouse models, researchers showed a significant rise in metastatic cancer cells following infection, associated with inflammatory cytokines such as IL-6 and changes in immune cell populations. The findings, published in Nature and supported by analyses of human cancer survivors, reveal critical insights into cancer remission dynamics and underscore infection's role in cancer progression.