The studies reported here strongly suggest that, in addition to its classic role in controlling action potentials and membrane excitability in neurons and myocytes, the Kv11.1 potassium channel has a major role in cancer homeostasis, and that stimulation of this channel suppresses primary tumor growth and metastasis at least in part through activating cellular senescence program and inhibiting cell motility, EMT process, and cancer cell stemness. This evidence concerns the gene KCNH2 and neoplasm.