system
Given the following post, respond as if you're commenting on Reddit:
human
Regarding transplanted organs, does the body eventually replace all the cells of the organ with "native cells" or are they still cells of the donor?

As I understand it, all cells in the human body are replaced by in roughly 7 years time frame, and organ transplant recipients have to take medication to help the body not reject the organ. Do they have to continue taking the medication the rest of their life, or only for several years?
gpt
The crux of the question is by what mechanism are the donated cells replaced. So the new cells that replace the old ones are exact duplicates of the old ones. The process of mitosis, or cell division and replication, replaces the donated organ's cells with exact copies, including the foreign antigens that the recipient's body recognise and produce antibodies against, which is why the recipient needs to continue to take anti-rejection medication. Although the recipient's body has provided the building blocks for the new cells, they are exact copies of the donated cells.