...contaminated by retrovirus present in the animals. Nowadays, programmes like CRISPR-Cas9 have succeeded in eliminating the genome in pigs which are bred specificially for this. Scientists now predict that in six or seven years a human will be able to receive ... will equal or even surpass transplants in forthcoming years, as is happening now in the USA. Also, 3-D technology will eventually be able to construct organs in vitro with cells, biomaterials and biological molecules. Would Juan Francisco Delgado, ... who had a transplant 32 years ago, accept a pig's heart? “Goodness... we'll have to see how things go, but I guess if it means you can lead a normal life... when you are in a terminal situation, like us, you're prepared to consider anything,” he says.