1. Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA.
2. Integrated Small Animal Imaging Research Resources (iSAIRR), Department of Radiology, University of Chicago, Chicago, IL 60637, USA.
3. Committee on Immunology, University of Chicago, Chicago, IL 60637, USA.
4. Committee on Cancer Biology, University of Chicago, Chicago, IL 60637, USA.