A biotech company recently announced that it's implanted another pig kidney into a human recipient. Here's what to know.

Cells are the smallest unit of life. Cells in multicellular plants and animals are arranged into tissues, organs and organ systems. Cells. Tissues. Organs. Organ systems. And the organism itself.

A milestone was reached in animal transplants in humans. In late January, an Alabama woman by the name of Towana Looney became the longest-living recipient of a pig organ transplant. She’s had ...

The controversy stems from the daunting immunological barrier to transplanting organs between disparate species and from the possibility that an animal organ or tissue might transmit an infectious ...