This book gathers relatively recent and significant topics in the field of ion channel research. Ion channels form the molecular basis for membrane excitability in cells present in the cardiovascular and nervous systems. In many non-excitable cells, ion channels contribute to diverse physiological functions, including the secretion of signaling compounds like hormones and insulin, cell volume regulation, intracellular signaling, especially Ca2+ signaling, etc. Many human diseases have been attributed to abnormal channel functions and defective membrane expression of channel proteins. On the other hand, ion channels are excellent models for studying protein biophysics, especially the allosteric regulation of protein function by miscellaneous stimuli. Therefore, research on ion channels carries significant meaning for the understanding of basic protein biophysics and diverse physiological functions. Such vital information also assists in developing novel and effective treatments for related human diseases. This book provides graduates and scientists in both basic and clinical levels a comprehensive understanding of cutting-edge advances and a useful and stimulating platform for tackling their own questions about ion channels.