Scientists across many disciplines are working to understand how the immune system affects, mediates, or even controls cancer growth in different parts of the body. This SU2C Cancer Susceptibility Convergence Research Team is using blood cells and other markers to intensively monitor the immune system over time in participants in three scientific research cohorts: an aging cohort, a twin cohort, and a cohort with inherited immunodeficiency. The results will be used to determine signatures of poor immune health that might predispose an individual to cancer. If successful, the findings will be a significant advance in medicine’s ability to understand what parts of the immune system are important in the prevention of cancer.