Hematopoietic stem cells (HSCs) are specialized cells found primarily in the bone marrow. They are responsible for producing all types of blood cells, including red blood cells, white blood cells, and platelets. HSCs have the unique ability to self-renew, meaning they can divide and create more stem cells, as well as differentiate into various blood cell types. These stem cells play a crucial role in the body's immune system and overall health. When the body needs to replenish blood cells, such as after an injury or illness, HSCs are activated to ensure a steady supply of new cells. This regenerative capacity makes them a key focus in medical research and treatments, including bone marrow transplants.