 Lateral phase separation within lipid bilayer membranes is a phenomenon observed in both living cells and model membrane systems. It is believed to play a role in the regulation of cellular processes, such as signal transduction and protein trafficking. In order to study this phenomenon, researchers have developed model membrane systems which can mimic the behavior of living cells. These systems allow scientists to observe and manipulate the physical properties of membrane phase separation under isothermal conditions. By studying these systems, researchers have identified three main factors that influence the formation of lateral phase separation, electrostatic interactions, chemical reactions, and membrane tension. Understanding how these factors interact can help us gain insight into the mechanisms behind membrane phase separation and its potential applications in cell engineering. This article was authored by Naofumi Shimokawa and Tsutomu Hamada.