Mesenchymal stem cells (MSCs), also known as mesenchymal stromal cells, are multipotent stromal cells that were originally identified in bone marrow in 1991. MSCs can differentiate into a variety of cell types including osteoblasts, chondrocytes, myocytes and adipocytes. MSCs have distinctive morphological features including a stem cell body with long thin processes containing a large round nucleus. MSCs are located in various tissues including bone marrow, cord cells, dental pulp, and amniotic fluid. MSCs have the ability to self-renew and differentiate, modulate immune responses, and exhibit antimicrobial properties, making them promising for clinical applications such as treating autoimmune diseases.