TOP2B and Myocardial fibrosis: The primary mechanisms of anthracycline cardiotoxicity involve the inhibition of topoisomerase IIβ (TOP2β), dysregulation of iron metabolism, mitochondrial dysfunction, myocardial fibrosis, sarcoplasmic reticulum calcium imbalance, oxidative stress, apoptosis, and aberrant microRNA (miRNA) expression (18) (Figure 1).