Transhuman by Ben Bova is a tired book about a maverick scientists whose work simultaneously enables him to reverse both cancer and the ageing process (with different side effects). So unlike books which, whether in fantasy or science fiction, have their characters set off on a quest for longevity treatment or the fountain of youth, this opens with the scientist sufficiently far off the beaten track of academic respectability, no-one wants to believe him when he announces he can cure his granddaughter’s cancer. This forces him into a kidnapping scenario so he can prove himself right. Because he’s seventysomething, he also doses himself with the anti-ageing treatment and slowly acquires the physique of a fortysomething as the book progresses. If you’re going to run from the FBI, you need to be reasonably fit. There are various ways in which this trope can be played out. Heroic tomb-robbers can be in competition with villains to find the Holy Grail, or villains have an evil plan which involves testing their product on unwilling volunteers with all kinds of unfortunate side effects appearing. Those who find themselves immortal (often Scottish) find life gets somewhat boring except for the occasional decapitation to liven them up, or get so depressed, they court death, e.g. as in the Company books.