Similarly, MMPs comprise another potential biomarker that could be used to assess the risk of CTRCD in breast cancer patients particularly on the late onset of anthracycline-induced cardiotoxicity [284,285], but further studies are needed to better evaluate the predictive role of MMP2, MMP9 and other MMPs for early and late stages of cardiotoxicity in breast cancer patients. This evidence concerns the gene MMP9 and breast cancer.