AUTHOR=Renovanz Mirjam , Kim Ella L. TITLE=Intratumoral Heterogeneity, Its Contribution to Therapy Resistance and Methodological Caveats to Assessment JOURNAL=Frontiers in Oncology VOLUME=4 YEAR=2014 URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2014.00142 DOI=10.3389/fonc.2014.00142 ISSN=2234-943X