By searching miRNA database (TargetScan, http://www.targetscan.org) for the prediction of miR-122 targets that may possibly contribute to doxorubicin resistance, we found that PKM2, which has been reported to be associated with drug-resistance and is the main form of pyruvate kinase isoenzyme (PKM) in cancers [14–15], might be a target for miR-122, whose 3’-UTR contains a highly conserved binding site for miR-122 (Fig 3A). Here, PKM is linked to cancer.