HDAC9 and ventricular ectopy: Chemotherapeutic agents, such as anthracyclines, alkylating agents, antimetabolites, histone deacetylase (HDAC) inhibitors, immunomodulatory drugs, platinum compounds, proteasome inhibitors, multitargeted tyrosine kinase inhibitors, vascular endothelial growth factor (VEGF) signaling pathway inhibitors, and immune check point inhibitors, are suggested to be associated with a broad range of arrhythmias, including sinus bradycardia and tachycardia, premature atrial complexes, supraventricular tachycardia (SVT), premature ventricular complexes (PVCs), and ventricular tachycardia (VT) (2, 7–11).