The article discusses the evolving understanding of Mesenchymal Stem Cells (MSCs) and their therapeutic potential. Initially, MSCs were recognized for their multipotent differentiation capabilities, particularly in bone, cartilage, and muscle tissue engineering. However, recent research has revealed that MSCs are primarily pericytes, cells that reside in the perivascular space of blood vessels. This discovery suggests that MSCs play a crucial role in maintaining vascular health and can be activated to modulate the immune response and promote tissue regeneration in response to injury. The authors propose that MSCs serve as site-specific "drugstores," secreting bioactive molecules that inhibit immune cell infiltration, prevent autoimmune responses, and support tissue regeneration. This role is particularly evident in preclinical animal models and clinical trials where MSCs have shown promise in treating various conditions, including heart disease, stroke, and autoimmune disorders. The therapeutic benefits of MSCs are attributed to their immunomodulatory and trophic activities, which can be harnessed to promote healing and repair. The article also highlights the importance of understanding the normal functions of MSCs and the need for further research to define the optimal clinical applications and modes of action of these cells. The potential of MSCs as therapeutic agents is significant, and the authors suggest that they should be considered as Medicinal Signaling Cells, emphasizing their role in modulating biological processes rather than just their differentiation potential.The article discusses the evolving understanding of Mesenchymal Stem Cells (MSCs) and their therapeutic potential. Initially, MSCs were recognized for their multipotent differentiation capabilities, particularly in bone, cartilage, and muscle tissue engineering. However, recent research has revealed that MSCs are primarily pericytes, cells that reside in the perivascular space of blood vessels. This discovery suggests that MSCs play a crucial role in maintaining vascular health and can be activated to modulate the immune response and promote tissue regeneration in response to injury. The authors propose that MSCs serve as site-specific "drugstores," secreting bioactive molecules that inhibit immune cell infiltration, prevent autoimmune responses, and support tissue regeneration. This role is particularly evident in preclinical animal models and clinical trials where MSCs have shown promise in treating various conditions, including heart disease, stroke, and autoimmune disorders. The therapeutic benefits of MSCs are attributed to their immunomodulatory and trophic activities, which can be harnessed to promote healing and repair. The article also highlights the importance of understanding the normal functions of MSCs and the need for further research to define the optimal clinical applications and modes of action of these cells. The potential of MSCs as therapeutic agents is significant, and the authors suggest that they should be considered as Medicinal Signaling Cells, emphasizing their role in modulating biological processes rather than just their differentiation potential.