Yes, absolutely. In fact, a significant portion of bone marrow transplant or stem cell transplants rely on finding matches from unrelated donors. Here's a breakdown:   

Allogeneic transplants use stem cells from a donor, and when a suitable family member isn't available, a search is conducted for an unrelated donor. This is where registries like "Be The Match" in the United States, and similar organizations worldwide, play a vital role.   

Donor Registries maintain databases of potential donors who have undergone HLA (human leukocyte antigen) typing. When a patient needs a transplant, doctors search these registries to find a matching donor. Therefore, many people receive life-saving transplants from complete strangers.

Finding a close HLA match is crucial for a successful transplant. Even though family members have a higher chance of being a match, many patients rely on unrelated donors. In essence, while family members are often the first choice, strangers are frequently the source of life-saving bone marrow or stem cell donations.   

Donating marrow to a stranger may have important psychosocial as well as physiological effects for the donor. Sometimes, the best chance for a successful bone marrow transplant is to find a donor who is unrelated to the patient. 

For more information visit the official site:: https://www.edhacare.com/treatments/organ-transplant/bone-marrow