When you bank your baby's cord blood stem cells, you preserve a unique biological resource that is like a "self-repair kit" for your child. Your baby's cord blood is a rich source of stem cells, which are the body's "master cells." These are genetically unique building blocks for blood, organs, tissue, and the immune system. Stem cells reproduce and differentiate into other cell types, including bone, heart, muscle, and nerve. In transplantation, stem cells differentiate into red blood cells, white blood cells, and platelets, the three types of cells necessary for healthy blood and a sound immune system. This is the miracle of cord blood.