Metastasis, 

Written and edited by experts in the field, this collection from Cold Spring Harbor Perspectives in Medicine covers the recent progress that has been made in understanding the molecular mechanisms underlying metastasis and how this knowledge is paving the way for new therapeutic targets. The
contributors discuss progress in defining mutations that might be driving metastasis, the formation of a premetastatic niche and how it enhances the establishment of a secondary tumor, and how changes that occur during aging increase the metastatic capacity of tumor cells. They also consider the
selection and colonization of common target organs (e.g., brain, liver, and bones) during metastasis and the roles of immune cells and extracellular vesicles at different steps of the metastatic cascade. Cellular plasticity-including evidence for metastatic stem cells and the role of tumor cell
dormancy in recurrent metastasis-is also covered.