Xerostomia, or dry mouth, is a debilitating condition often experienced by individuals undergoing radiation therapy for head and neck cancer or those with autoimmune Sjögren’s disease. Current treatments for xerostomia provide limited relief, prompting exploration of alternative solutions such as artificial salivary glands, gene therapy, and cell-based interventions. Understanding stem cell regulation is crucial for advancing salivary gland regeneration, leading to systematic research focused on identifying key regulators for cell lineage determination. This chapter summarizes the primary inductive signals involved, including extrinsic factors from the microenvironment and cell-intrinsic factors that drive the differentiation of stem cells into pancreatic, liver, and salivary gland cells—organs that share an endodermal origin. Insights from studies on pancreatic and liver regeneration inform key signals involved in orchestrated stem cell differentiation for salivary epithelial cells. Examples of transdifferentiation between differentiated cells from different organs and the in vivo application of inductive factors offer valuable perspectives on future clinical applications, enhancing both safety and effectiveness.