What does Kazuo Ishiguro try to tell us through his novel Never Let Me Go ? What is it all about?

The novel points a dystopian future where human beings are cloned to provide a supply of organs for transplant. This practice, while based in science and a plausible topic for a work of speculative fiction, is also a rich metaphor that may be at the root of the author's purpose in telling the story. The clones, who don't have parents and who are wards of the state, who are in fact possessions of the state, could be seen to represent the poor or underprivileged classes of Great Britain. They are treated not only a ssecond-class citizens, but as subhuman. The belief that they are not truly human, and that their expressions of emotion or creativity are simply glitches and not evidence of their having a soul, could be seen to parallel the notion, not unheard of in modern Britain, that the lower classes are intellectually and socially inferior to the upper classes. This reinforcement of social hierarchy is a theme that also occurs in other novels by Ishiguro.
It is also not inappropriate to suggest that the novel offers a commentary on the breakdown of the medical industry in Great Britain, which once had one of the finest healthcare systems in the world. Its transition from socialized to partly privatized has been disastrous, and the novel could be exploring what it would mean for the rich to be the recipients of the best medical care while the poor are exploited by this system.