Organs from gay men or injecting drug users, often rejected for transplants, could safely be used, so long as donors test negative for infections such as HIV, and hepatitis B and C.
The idea behind regenerative medicine is that the patient is both the donor and recipient of healthy tissue grown from stem cells. But sometimes the transplanted cells are rejected. Now we know why.
Doctors can treat diabetes by transplanting cells from the pancreas of a donor to the patient. But many of the crucial cells die - a better way to store and transport them can help.
Health benefits come with regular sexual contact with the same male partner before pregnancy commences.
Italian surgeon, Sergio Canavero, claims that he is ready to perform the world's first head transplant. But does the science stack up?