Generally speaking, the American public is well accustomed to the concept of tissue and organ transplantation, as stories of life-saving heart and kidney transplants, or American Red Cross blood drives collecting blood and platelets for transfusions have become commonplace. Since these procedures typically require a transfer of tissue from one patient to another, physicians must be careful to choose well-matched donors to avoid rejection by the recipient’s immune system. But what about other specialized tissues that can be affected by disease, such as those of the eye? A recent study published in the journal Stem Cells by Winston Kao and...