We learn from one another and build upon each other. This is never more true than in the medical sciences where hideous tests on prisoners of wars translated into hypothermia treatment and understanding the process of wound healing.
Radical bioinformatics that will make all experiments in silico is still some time away, so scientists who want to study biological processes but don't work with live animals (either in vivo or in situ) commonly use tissue culture from derived cell lines. The most famous of which are the HeLa cells that was derived from the tumours that riddled Mrs. Henrietta Lacks, an African American woman who died of cancer in 1951.
The thing was, permission was not obtained from Mrs. Lacks' family to obtain the sample by either the physician who took the sample nor Dr Gey, the guy who propagated the cell line. Mrs. Lacks has been described as "a black woman whose body had been exploited by white scientists".
Frankly, I get Dr Gey's situation; you get samples for your experiment, you don't tend to question too much. After all, they are hard to come by. These days, what with university and hospital ethics committee having a voice in how you conduct your research, these sort of things are in the past. As the idea for informed consent evolve and people began to understand and assert their rights, no one will blindly sign forms just because someone in a white coat told them to do so.
Then again, may be not. Ask anyone who has to collect human samples for their research experiments.
But I digress.
The issue here is her tissue (notice the alliteration? I'm kinda proud of it XD). Although Dr Gey received no monetary rewards from the development of the cell lines (or so it stated), but there have been hundreds of inventions and innovations that had come about thanks to these ever multiplying immortalised cells. If the decendants of Arthur Conan Doyle could still dictate the way the source material of Sherlock Holmes is treated (and getting paid gobs of money for the right), why shouldn't her children, who are also not well-off and presumably struggling, benefit from the companies who have made millions out of the cells that had killed their mother?