Paracrine signaling is a form of cell-cell communication in which a cell produces a signal to induce changes in nearby cells, altering the behavior or differentiation of those cells.he Wnt signaling pathways are critical in cell-cell signaling during normal development and embryogenesis and required for maintenance of adult tissue, therefore it is not difficult to understand why disruption in Wnt signaling pathways can promote human degenerative disease and cancer.