"Vitals" by Greg Bear

Vitals is SF in that it involves biotech which (presumably) does not really exist today. But to me, it's more of a conspiracy theory novel.

The story is set more-or-less today. The not-real-today biotech doesn't introduce us to any whiz-bang hi-tech. The biotech that the book revolves around is more "different" than it is "futuristic". In that sense and in the sense of the story of its origins, the book might be said to have one foot in the alternative history genre. Its tangle of clues and activities puts it in the area of intrigue fiction.

We are led into the maze of world-wide intrigue by a pair of identical twins. They have gone their separate ways as far as personal lives go, but have followed closely related professional lives. Each is following research on the means to greatly extend human lives. Each is approaching it in essentially the same framework, believing the secret lies with the ancient emergence of cells combining primitive cells with bacteria. They theorize that something in that symbiotic relationship isn't quite right and results in our aging before we have to. To explore this they seek out where very old forms of life still exist on Earth.

Apparently, somebody somewhere doesn't like the focus of their researches. Strange things start to interfere with their efforts. Strangers start doing strange things against them with no obvious connection. A once-respected historian (now a generally-shunned anti-Semitic pundit) approaches one of the brothers with documentation about a mind control conspiracy.

As the biotech and conspiracy investigations go ahead, attacks by strangers and neighbors escalate. Suspicious things are noticed. And the two brothers, separately on their own, carry out some initial experiments on themselves.

This may not be the kind of book about which I should tell more of the story.

The book will appeal to many biotech thriller fans. Perhaps more so to fans of conspiracy / espionage fiction. People who like a broad range of speculative fiction might also pick this book. Those who prefer something more futuristic may want to look elsewhere. While any speculative fiction will give some food for thought, I would not recommend this for someone looking for a "thought-provoking book".