–Knockdown reduces proliferation, induces an arrest at G0/G1 and increases apoptosis of MG-63 osteosarcoma cells–Downregulation of both Kv1.5 and Kv1.3 protects macrophages from staurosporine-induced cell death–Knockdown protects endothelial cells from palmitate-induced apoptosis–Inhibition with 1 μM DPO-1 rescues the suppression of proliferation and induction of apoptosis mediated by apogenin in pulmonary artery smooth muscle cells–Inhibition with 0.3-3 mg/kg DPO-1 rescues H2O2-induced endothelial cell apoptosis. Here, KCNA5 is linked to osteosarcoma.