**2. The importance of ion channels in oncology**

Ion channels represent the second biggest protein family in the human genome after GPCRs. These proteins allow the flux of ions through the plasma membrane.

Kv.10.1 (also known as Eag1) is dependent on membrane voltage, and after a depolarization, it allows the efflux of potassium ions out of the cell into the extracellular space in a time range of milliseconds. After the exit of K ions, the consequent change in membrane voltage will then function as a cellular signal. If we analyze the protein structure of Kv10.1 we identify a transmembrane region and a big intracellular domain which represents almost 50% of the whole protein [1]. Such a long cytoplasmic domain reveals the importance of the channel not only as a K ion gate but also as an interactive partner of signaling molecules. Canonical functions of voltage-gated potassium channels encompass action potential repolarization, control of resting potential and excitability and volume control. However, more than 70 different genes encode voltage-gated potassium channels and they are expressed in excitable cells as well as in non-excitable cells. This fact suggests that voltage-gated ion channels are involved in more processes beyond action potential definition, as has been demonstrated in the last decades.
