Haploidentical transplantation is a type of stem cell transplantation where the donor is a partial match (usually a parent or sibling) and shares half of the donor's genetic material. This type of transplantation is often used when a fully matched donor is not available, and it has been shown to be a successful alternative in certain cases. Haploidentical transplants involve specialized techniques to reduce the risk of complications and rejection, making it a promising treatment option for patients in need of a stem cell transplant.