Comment on

• The identification and characterization of breast cancer CTCs competent for brain metastasis.

  Zhang L, Ridgway LD, Wetzel MD, Ngo J, Yin W, Kumar D, Goodman JC, Groves MD, Marchetti D. Zhang L, et al. Sci Transl Med. 2013 Apr 10;5(180):180ra48. doi: 10.1126/scitranslmed.3005109. Sci Transl Med. 2013. PMID: 23576814 Free PMC article.
• Identification of a population of blood circulating tumor cells from breast cancer patients that initiates metastasis in a xenograft assay.

  Baccelli I, Schneeweiss A, Riethdorf S, Stenzinger A, Schillert A, Vogel V, Klein C, Saini M, Bäuerle T, Wallwiener M, Holland-Letz T, Höfner T, Sprick M, Scharpff M, Marmé F, Sinn HP, Pantel K, Weichert W, Trumpp A. Baccelli I, et al. Nat Biotechnol. 2013 Jun;31(6):539-44. doi: 10.1038/nbt.2576. Epub 2013 Apr 21. Nat Biotechnol. 2013. PMID: 23609047