Juxtacrine signaling is a type of cell communication that occurs when two cells are in direct contact with each other. In this process, signaling molecules on the surface of one cell interact with receptors on the adjacent cell. This interaction can influence various cellular functions, such as growth, differentiation, and immune responses. This form of signaling is crucial in many biological processes, including embryonic development and immune system responses. Unlike other signaling methods, such as paracrine or endocrine signaling, juxtacrine requires physical proximity between the cells, making it essential for localized communication in tissues.