Our understanding of how and when breast cancer cells transit from established primary
tumors to metastatic sites has increased at an exceptional rate since the advent of in vivo
bioluminescent imaging technologies 1-3. Indeed, the ability to locate and quantify tumor
growth longitudinally in a single cohort of animals to completion of the study as opposed to
sacrificing individual groups of animals at specific assay times has revolutionized how
researchers investigate breast cancer metastasis. Unfortunately, current methodologies …