These are cells from a person, Henrietta Lacks, which can be grown in a dish and which keep dividing, for ever.
HeLa cells are certainly the most famous. It should be noted that the HeLa stocks used in most labs now are radically different from original HeLa stocks.
Even in routine experiments, you have to keep a bunch of cells frozen in liquid nitrogen to replenish your "working stock" of cells. After around 30-40 passages (e.g. generations of cells), most immortalized cell lines start to get funky with mutations and exhibit different behaviors. You kill them off and go back to your frozen stocks to get back to the "original" genetics.
Patenting a human cell? That's the most absurd thing I've ever heard.
These cell lines do not exist in nature and what is patented was the creation of a new immortalized cell line.
But I have a sinking feeling that it could.