AUTHOR= Frontiers Editorial Office TITLE=Expression of Concern: Mechanism of Action of the Novel Nickel(II) Complex in Simultaneous Reactivation of the Apoptotic Signaling Networks Against Human Colon Cancer Cells JOURNAL=Frontiers in Pharmacology VOLUME=7 YEAR=2016 URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2016.00190 DOI=10.3389/fphar.2016.00190 ISSN=1663-9812