Provided is an efficient method of inducing differentiation of a pulp cell into an odontoblast. A protective film formed from the photosensitive polysiloxane composition and an element including the protective film are also disclosed. The broadcast information includes information about the current cell’s shape and translational and rotational motion. A memory module adapted for use in the memory system has four contacts arranged at both ends and on both surfaces. The method includes preparing a pair of unit panels respectively comprising display devices, etching main bodies of the pair of unit panels, and connecting the pair of unit panels so that etched portions of the main bodies of the unit panels overlap in a thickness direction of the unit panels.