AUTHOR=Santoni Matteo , Cimadamore Alessia , Cheng Liang , Lopez-Beltran Antonio , Battelli Nicola , Massari Francesco , Scarpelli Marina , Galosi Andrea Benedetto , Bracarda Sergio , Montironi Rodolfo TITLE=Circulating Tumor Cells in Renal Cell Carcinoma: Recent Findings and Future Challenges JOURNAL=Frontiers in Oncology VOLUME=9 YEAR=2019 URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2019.00228 DOI=10.3389/fonc.2019.00228 ISSN=2234-943X